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I MAY, 1917 



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2TRICAL. NEWS 




ILLUSTRATED 



LECTRIC TORPEDO 
DESTROYER 



•SEE PAGE 10 




LARGEST CIRCULATION OF ANY ELECTRICAL PUBLICATION 




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Yes, entirely free. Our big, new electrical cyclopedia No. 18 is waiting 
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2 



THE ELECTRICAL EXPERIMENTER 



May, 1917 




FREE! 20 lessons 



Write me at once — TODAY! Just send the coupon or a postal. I will give you 
20 complete lessons in practical electricity FREE ! Think of it ! My personal and 

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these 20 lessons now or later. I make this sensational offer to secure a few more live students — to show, 
too, how quickly I can make you a Master Electrician no matter where you live, or what you do. But you 
must act at once! This offer closes in 23 days! Remember these free lessons are not merely sample 
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electricity or never had a bit of electrical experience, I will take you in hand and make you an Expert 
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I Train You By Mail! Men Wanted 




Formerly with the General 
Electric Co.; former General 
Manager of company manu- 
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tors; also formerly with Fair- 
banks, Morse & Co.; now Con- 
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of the Wicks Electrical Insti- 
tute. 



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A. W. WICKS, E. E„ Director 

Wicks Electrical Institute 

81 W. Randolph St., Dept. 295 Chicago, 111. 



State. 



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The Electrical Experimeeter 



233 Fulton Street, New York. 
Publisht by Experimenter Publishing Company, Inc. (H. Gernsback, President; S. Gernsback, Treasurer;) 233 Fulton Street, New York 



Vol. V Whole No. 49 



CONTENTS FOR MAY, 1917 



No. 1 



ELECTRIC TORPEDO DESTROYER— Front Cover 

From a painting by George Wall 

A ONE-MAN ELECTRIC SUBMARINE By II. Winfield Secor 

ELECTRIFYING THE AEROPLANE 

THE AUTOGRAPH OF YOUR HEART By Samuel Cohen 

COMBATING THE SUBMARINE By H. Gernsback 

SOURCES OF ELECTRICITY 

MAGNETISM PRODUCES REMARKABLE PHOTOGRAPHS.. 

By F. F. Mace 

THE THERAPY OF LIGHT AND THE NEW "R-RAY" 

By H. Rosenthal 

"EDDY CURRENTS"— A Scientific Story By C. M. Adams 

THE WASHINGTON'S BIRTHDAY RELAY PRIZE WINNERS 

By W. II. Kirwan 

ELECTRICITY AND LIFE— Second Paper 

By Dr. Frederick Finch Strong 

EXPERIMENTAL PHYSICS — Fourth Lesson 

Bv John T. Furia, A.B., M.A., F.K.S. 
WIRELESS TELEGRAPHY— THE MARCONI HIGH POWER 



Hi 
12 



IS 

20 



23 



24 

25 



TRANS-OCEANIC STATIONS 

By E. B. Pillsbury, Marconi Wireless Telegraph Co. 

HOW THE AUDION REPEATER REPEATS 

THE IONIC RADIO SYSTEM AND THEORY OF IONIC 

TUNING By Otto E. Curtis, A.M., I.R.E. 

RECEIVING MARCONI 300 K.W. SPARK STATIONS WITH 

OSCILLATING AUDION 

By Samuel Curtis, Jr., R.E., U.S. Navy 

DISTRIBUTED CAPACITY AND ITS EFFECT 

By Samuel Cohen 

A STUDY OF THE LAW OF RESPONSE OF THE SILICON 
DETECTOR ; • • ; ■ 

CONSTRUCTOR DEPARTMENT— AN ELECTRICAL PARA- 
DOX OR SELECTIVE LAMP CONTROLLER 

By Albert H. Beiler 

AN ILLUMINATED STAGE SULKY.... By Harry S. Townsend 
A SIMPLE ELECTRIC MOTOR ATTACHMENT FOR PHONO- 
GRAPHS By R. U. Clark, 3d 

EXPERIMENTAL CHEMISTRY— Twelfth Lesson ■■ ■• 

By Albert W. Wilsdon 



26 
30 



31 



34 



3K. 



40 





HE Radio Act of 

states : 

Every such license shall provide that the 
President of the United States in time of 
war or public peril may cause the closing 
of any station for radio communication 
and the removal therefrom of all radio apparatus, or 
may authorize the use or control of any such station 
or apparatus by any department of the Government, 
upon just compensation to the owner. 

We now stand on the threshold of war; indeed, be- 
fore this issue is in the hands of our readers war will 
have been declared, or what is equivalent, this coun- 
try will be in a state of war. 

Let us then be perfectly frank with each other, and 
let us face the situation as it behooves upright, pat- 
riotic, law-abiding citizens. The European war has 
taught us that messages sent from secret radio plants 
by spies have been of priceless value to the enemy. 
Small wonder then that hysteric officials of all the war- 
ring nations have exterminated every possible as well 
as impossible private wireless plant in their respect- 
ive countries. But to what good? True, every sta- 
tionary outfit has been dismantled or confiscated by 
the warring Governments, but as always : where there's a 
will there's a way. When the German spies in England 
and in France found that it was not very healthy to op- 
erate their outfits in attics or in house chimneys — for a 
sending outfit is soon located — they simply put their 
radios in touring cars, cleverly concealing the aerial 
wires inside of the car bodies. The apparatus too were 
easily concealed, and the English and French were 
outwitted simply because you cannot locate a moving 
radio outfit except by pure chance. 

Which brings us face to face with the question : 
Did it pay the warring nations to kill the few private 
Radio stations they had before the war? We are 
honestly inclined to believe that far from being an ad- 
vantage, it proved an actual disadvantage. No one at 
all familiar with the technique of the radio art, doubts 
for one minute that if a spy has the courage as well 
as the funds — and spies always have both — he cannot 
be stopt from sending wireless messages if he elects 
to do so. Working under cover and by moving from 
one place to another, nothing will stop him. 



If we recognize this truth 
it is to close all privately owned radio stations during 
the war. It will doLno earthly good and can do only 
actual harm. Now we do hot wish to appear selfish, 
nor do we wish to be classed as unpatriotic. Very 
much the contrary. If the administration, after care- 
fully considering all the facts, decides to close all 
privately owned radio stations in this country, we 
will not as much as raise a single word of protest. 
The administration knows what is best for the wel- 
fare of the country and in time of national peril we 
would be the last ones to annoy our officials. 

But is it not true that our splendid body of over 
300,000 patriotic American Radio Amateurs, scattered 
thickly all over the country, can be of inestimable 
value to the Government? Can not our red-blooded 
boys be trusted to assist our officials in running down 
spies, who probably would not be readily located 
otherwise? In our big cities thousands of ears lis- 
ten every minute of the day to what is going on in the 
vast ether-ocean. Trust our very capable American 
youths to ferret out the senders of questionable sig- 
nals or strangely worded messages. The very multi- 
tude of these amateurs is a priceless protection. Then 
again both our Army and Navy badly need Radio 
operators. What other country can furnish such a 
vast army of well trained and intelligent operators 
as ours, thanks to the amateurs? 

When in 1916 the writer organized the Radio League 
of America, he incorporated in its statutes that every 
member should pledge in writing his station to the 
Government. Up to this moment the League has for- 
warded to Washington thousands of such pledges, 
among them every important amateur station in the 
country. These stations can be used by the admin- 
istration at a moment's notice. At least our amateurs 
are fully prepared. 

Would it not be questionable wisdom to shut down 
all these stations that can and will do enormously more 
good than possible harm? 

Let our officials ponder and let them consider fairly 
the facts in the case. That is all that we desire. 

H. GERNSBACK. 



THE ELECTRICAL EXPERIMENTER is publisht on the 15th of each 
month at 233 Fulton Street, New York. There are 12 numbers per year. Sub- 
scription price is $1.50 a year in U. S. and possessions. Canada and foreign countries, 
$2.00 a year. U. S. coin as well as U. S. stamps accepted (no foreign coins or stamps). 
Single copies, 15 cents each. A sample copv will be sent eratis on request. Checks 
~nd money orders should be drawn to order of THE EXPERIMENTER PUB- 
LISHING CO., INC. If you change your address notify us promptly, in order 
that copies are not miscarried or lost. A green wrapper indicates expiration. 
No copies sent after expiration. 

All communications and contributions to this journal should be addrest 
to: Editor, THE ELECTRICAL EXPERIMENTER, 233 Fulton Street, New 



York Unaccepted contributions cannot be returned unless full return postage 
has been included. ALL accepted contributions are paid for on publication. A 
special rate is paid for novel experiments; good photographs accompanying them 
are highly desirable 

THE ELECTRICAL EXPERIMENTER. Monthly. Entered as second- 
class matter at the New York Po«t Office, under Act of Congress of March 3, 1879. 
Title registered U. S. Patent Office. Copyright, 1917, by E. P. Co., Inc., New 
York. The contents of this magazine are copyrighted and must not be 
reproduced without giving full credit to the publication. 

THE ELECTRICAL EXPERIMENTER is for sale at all newsstands in the 
United States and Canada; also at Brentano's. 37 Avenue de l'Opera, Paris. 



3 



4 



THE ELECTRICAL EXPERIMENTER 



May, 1917 




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ROTARY VARIABLE CONDENSER 

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ONLY A FEW 

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You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 




THE ELECTRICAL 
EXPERIMENTER 



H. GERM5BRCK editor 
H. W. 5ZZDR /J55DcmTE editor 



Vol. V. Whole No. 49 



MAY, 1917 



Number 1 



A One-Man Electric Submarine 



WHILE Henry Ford has been 
urgently advocating the use of 
a one-man submarine of more 
or less efficacy, and compris- 
ing among other things a long 
collapsible pole extending from the minia- 
ture submarine, on the end of which there 
is supposed to be placed a torpedo or bomb 
which is to be exploded by the operator 
within the submersible, a number of other 
enterprising inventors have been engaged on 



By H. WINFIELD SECOR 

ception of one of these demons of war 
making its attack on the hull of a mighty 
Dreadnought, with a magnetic bomb prop- 
erly timed to explode a few minutes after 
its attachment, in order to give the opera- 
tor of the one-man submersible sufficient 
time in which to get far enough away from 
his victim to protect himself. 

In the first place, it is the inventor's idea 
to make up these miniature submersibles 
of about the same size as the modern auto- 



at two hundred horse-power for the above 
range, if the craft is to make a speed of 
42 knots or approximately 50 miles per 
hour. In the event that the navigator of 
such a submersible should have to make a 
detour in order to get back to* the mother- 
ship or to his shore base, it would be ad- 
visable to equip the boat with an auxiliary 
gasoline engine as shown in the accom- 
panying illustration. 'Most probably un- 
der ordinary conditions, the operator of 




The One-man Electric Submarine Here Shown in Detail and Also in Action Has Considerable Promise. It Can Dart Thru the Water at 
Torpedo Speed (50 miles per hour) When, Having Attached Its Magnetic "War-head" Containing the Gun-cotton and a Time Fuse to the 
Hull of an Enemy Vessel, It Can Easily and Quickly Make Its Escape at Mile-a-minute Speed. It Should Prove Ideal for Coast and 

Harbor Defense. 



a similar yet somewhat different problem. 
One of the most promising of these designs 
for a one-man submarine is that of Mr. 
■Eric R. Lyon, the engineer who was respon- 
sible for the mastodonic two-hundred-foot 
high electric gyro-cruiser featured in our 
February, 1916, issue. 

The accompanying illustration shows a 
detailed view of a one-man electro-me- 
chanical submersible along the lines laid 
down by Mr. Lyon, and also an artist's con- 



Harbor Defense 

mobile torpedo, or measuring say 25 feet 
long by 3 feet in diameter. This com- 
pares approximately with the dimensions 
of the latest type U. S. torpedo' with a 
range of ten thousand yards or 5.7 miles. 
When comprest air is utilized for propul- 
sion, the air being stored in the tank at two 
thousand pounds pressure to the square 
inch, the comprest air engine used in the 
modern torpedo (and which could be adap- 
ted to the one-man submersible) is rated 



this new war engine would have no trouble 
in getting back to his base of operation by 
means of the comprest air equipment. It 
has been claimed by Mr. Ford and other in- 
vestigators that it is now possible to op- 
erate a gasoline engine under water by 
means of special absorption apparatus at- 
tached to the exhaust manifold of the gas- 
oline or other engine, and that this means 
of propulsion can be attached to submarine 
war vessels. If such is the case, then it 



6 



THE ELECTRICAL EXPERIMENTER 



May, 191 7 



"ELEVATING" CENTRAL. 

The upper stories of the West Palm 
T.each Telephone Company's office in Flor- 
ida, which has just, had two floors added 
to it, was the scene of a remarkable en- 
gineering feat recently. 

Under the new arrangement it became 
necessary to remove the big switchboard, 
at which the operators sit and make the 
connections that enable people to communi- 
cate with each other on an infinite var- 
iety of subjects, important or affectionate 
or merely frivolous, from the third to the 
fourth story. The move was made in the 
following simple but effective manner. 

A platform composed of two pieces of 
4x6 timber, on which was laid a floor of 



2x12 planks, was built under the heavy 
switchboard — wide enough to accommodate 
the operators' chairs around the edge of 
the board. Slings were then placed about 
the whole business, to which a tackle and 
three heavy differential blocks, each cap- 
able of handling a weight of four tons, 
attached to a sling of log chains fastened 



to a heavy beam at the top of the fifth 
story. 

The switchboard, with the girls seated 
at it, and still carrying on their work, 
was hoisted thru a hole in the floor of the 
fourth story. 

The work was carried on without a hitch, 
and the girls remained suspended until 
the floor had been rebuilt under the switch- 
board. There was not the slightest inter- 
ruption to business from first to last dur- 
ing the ascent. Nor did the subscribers, 
talking over the switchboard, suspect in 
their wildest utterings, that "Central" 
Switchboard Girls — chewing gum and all — 
were moving skyward, angel-like, all the 
while. 




Right: — At Last! Central's Eleva- 
tion Completed. No interruption 
in Traffic and the Girls Are 10 Feet 
Nearer Heaven. 



will mean that the one-man submarine will 
become all the more practicable. 

Coming down to the means whereby this 
novel engine of war is to be used in car- 
rying out offensive operations, we see upon 
looking over the detail drawing that in front 
of the submarine there is a detachable war- 
head in the form of a steel cap which fits 
against the parabolic nose of the subma- 
rine very tightly. This war-head contains 
the usual quantity of gun-cotton or other 
high explosive. Suitable quick-acting mag- 
netic clutches enable the operator to in- 
stantly release the entire war-head ait any 
desired moment. 

This submersible not only carries two dis- 
tinct forms of prime mover, but also car- 
ries the necessary gas tanks to supply a 
set of ultra-powerful oxy-acetylene flame 
nozzles, suitably disposed about the for- 
ward part of the vessel on the exterior, and 
by means of which the operator can burn 
his way thru any ordinary submarine net 
entanglement. 

This feature is one of the latest scien- 
tific discoveries and involves the operation 
of an oxy-acetylene flame under water, 
which is made possible by blowing a stream 
of comprest air around the gas nozzle, and 
in this way forming a flame pocket in the 
•water so to speak. 

Mr, Lyon is very enthusiastic on this par- 
ticular innovation, and has drawn plans for 
a one-man submarine which utilizes an ex- 
tra powerful and especially contrived set of 
these high power oxy-acetylene nozzles with 
which to burn a hole thru the bottom of 
a Dreadnought, causing it to founder soon- 
er or later. 



Among the other interesting features of 
the idea here pictured we find a collapsible 
periscope which may be folded down into 
a suitable pocket provided in the top of the 
hull, and attached to which there is an air 
tube and also a (distress) rocket shute. 
When running submerged, a special air 
machine is used to supply the necessary- 
oxygen to the navigator. A powerful elec- 
tric searchlight is fitted to the front of the 
detachable war-head and by means of the 
small periscope shown the operator can see 
ahead at a considerable distance ufider the 
water. A compact but powerful battery is 
contained in the war-head which can sup- 
ply sufficient energy to energize the electro- 
magnets which hold the explosive chamber 
to the hull of the enemy war vessel once 
the operator has managed to approach close 
enough to accomplish this result. 

The war-head also carries a special elec- 
tric time switch, which functions a few 
minutes after the war-head has been at- 
tached magnetically to the hull of the ene- 
my vessel, and which causes an electric 
spark to detonate the gun-cotton charge. 

It has been argued by a number of naval 
experts that the One-man Submarine is 
doomed to failure for several different rea- 
sons. This, however, does not seem to be 
the case so far as we can see, and provid- 
ing the submersible is nroperly designed in 
its details. 

Let us take a concrete case for example 
to show how the Lyon one-man ship de- 
stroyer would go about its task. 

Assuming that these engines of destruc- 
tion, of which there would be most prob- 
ably several in each attack to make doubly 



sure that the enemy would not escape, have 
been despatched either from a fort or oth- 
er point on the coast, or from a mother-ship 
several miles *-.stant from the enemy, the 
intrepid navigator of the 50-mile-an-hour 
submarine starts forth on his perilous jour- 
ney. With only his periscope exposed and 
at a distance of several miles, it is well 
known that a periscope projecting a foot or 
so above the water presents an almost im- 
possible target for ordinary gun-fire, and 
moreover, as the vessel darts forth on its 
way and as the range decreases between 
himself and the enemy, the buoyancy and 
submerging tank motor-pumps are manip- 
ulated so that only occasional sightings 
are made with the periscope. It thus be- 
comes very problematical whether the ene- 
my could hit the submarine. Also at a 
distance of say one mile, and in accordance 
with standard submarine maneuvering the 
submarine officer then proceeds to take ac- 
curate sightings of the enemy both with 
regard to the range and the direction geo- 
graphically, after which he submerges and 
may proceed at high speed at a depth of 
fifteen to twenty feet below the surface of 
the water (the same as modern torpedoes) 
and in a little over a minute or so, 'and 
providing he has gaged the enemy's posi- 
tion accurately, he will find himself in the 
vicinity of the bottom of the hull. Owing 
to the high speed possible with this minia- 
ture submarine, built like a torpedo, it 
should be possible for the navigator (in 
the event that he does not strike his mark, 
when he has gone the range calculated up- 
(Continaed on page 47) 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



Electrifying the Aeroplane 



ELECTRICITY is being rapidly in- 
troduced in the new art of Aero- 
nautics as the illustrations herewith 
tend to testify. The greatest de- 
velopment in the art of flying is 
■the aerial limousine or so-called Autoplanc 
illustrated in Fig. 1, which was exhibited 
.at the recent aeroplane show held in New 
York City. This aeroplane is built in the 
form of an automobile limou- 
sine and equipt with three 
•planes for the sustaining sur- 
face. Aside from its perfect 
-mechanical features its electri- 
cal equipment is exceedingly 
interesting, as the engine is 
automatically started by means 
■of an electric motor installed 
•exactly the same as the mod- 



the minimum air speed has been reached. 
It is mounted in any convenient position 
where the air flow is unobstructed. 

The stallemometer is adjustable for any 
desired air speed, depending on the aero- 
plane on which it is installed. When the 
predetermined speed is reached, an electric 
contact is closed in the stallemometer, clos- 
ing the circuit thru an indicating lamp 



I Fig. 3. Electrically \ 

I operated "Incidence 

m Indicator" for show- 

I ing best gliding and } 

J| climbing angles. 1 




Fig. 2. The electric 
"Stallemometer" warns 
the aviator, when his ma- 
chine is approaching a 
stalling condition by indi- 
cating that the minimum 
air speed has been 
reached. 




at a dangerous angle. The white lamp sig- 
nals whenever the pilot dives at too steep 
an angle. The green light indicates the best 
climbing angle. Being of low voltage as 
well as low current consumption, the lights 
can be operated on a dry battery, encased 
in metal and installed wherever most con- 
venient. The signals are regulated by a 
vane operated by the air stream. 

The lamp bank container is 
seen in the background. Each 
lamp is equipt with the proper 
colored screen and each con- 
nected to the required contacts 
enclosed in the incidence indi- 
cator chamber. The lead wires 
are led thru one of the support- 
ing tubes. 

Aviators wishing to know at 



Fig. 1. The latest in flying machines 
— the "Autoplane." It is an aerial 
limousine. 



Fig. 4. Dead-beat 
"Clinometer" which 
shows angle of aero- 
plane with the earth. 






Fig. 5. The "Sperry Automatic Pilot" which, by means of elec- 
tric driven gyroscopes, serves to control and maintain an aero- 
plane in any desired position: the pilot may drop bombs, etc. 



-em automobile engine electric starter. The 
■engine develops 100 horsepower and drives 
a four-bladed propeller place at the rear. 
The interior lighting is aecomplisht entire- 
ly by electric lamps and its ignition is of 
the very latest electrical design. Altho it 
-may seem that the machine was not made 
for speed, yet it has a speed range of sixty- 
five miles per hour and can si ;tain a weight 
of 710 pounds. It can carry two passen- 
gers and a pilot. 

The stallemometer illustrated in Fig. 2 
i's an electric instrument devised to warn 
the aviator when his machine is approach- 
ing a stalling condition by indicating that 



mounted on the instrument board stationed 
in front of the pilot. 

An incidence indicator increases the effi- 
ciency of an aeroplane by warning the avia- 
tor before he stalls and by enabling him to 
get the best climbing and gliding angles out 
of his machine. 

The transmitter of the Incidence Indica- 
tor in Fig. 3, is mounted on a forward strut 
so as not to interfere with any part of the 
plane. The lamp bank or indicator is on 
the instrument cowl, always visible to the 
pilot observing other essential instruments. 
The red light warns the aviator before he 
stalls as well as when he begins climbing 



any time the correct 'fore and 'aft posi- 
tion of the machine, with reference to the 
horizontal, can read it on the scale of the 
dead-beat clinometer illustrated at Fig. 4. 

The operation of this instrument is sim- 
ple. Whenever the clinometer is tipt for- 
ward or backward by the motion of the 
plane, this movement is registered on a scale 
mounted on a wheel which is damped by 
floating in a liquid. 

If the aeroplane tips forward, the scale 
moves upward, indicating in degrees below 
the zero line the exact angle. If the ma- 
chine tips backward, the scale moves down- 
( Continued on pane 54) 



8 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



The Autograph of Your Heart 

By SAMUEL COHEN 



ONE of the most important mech- 
anisms of the human body is the 
Heart. Its action in health and 
disease has been the subject of 
attention by numerous prominent 
physicians in all parts of the world, par- 




Showing How the Extremely Sen- 
sitive Electrical Apparatus Is 
Connected up to Patient in Scien- 
tifically Determining Just How 
the Heart Beats and Why. The 
Apparatus Used for this Meas- 
urement Is Known as the "Elec- 
trocardiograph." (Fig. 2.) 

ticularly those interested in fighting heart 
disease, the most unrelenting malady with 
which one can be stricken. Yet it has 
been said that 15,000 to 20,000 school chil- 
dren in New York alone are suffering 
from it. 

In view of its most important function 
and delicate structure, cure, by way of 
operation, is usually im- 
possible. Therefore, the — — 
only thing left is to care- 
fully study the heart, lo- 
cate the trouble and de- 
termine the reasons for 
this trouble. A first aid 
in this direction is a bio- 
graphical history of the 
patient. 

The rapid growth of 
this disease, and the rapid — — — - 
advancement of science ~ ^^^^™^^~ 
has led to the devel- 
opment of a new instrument called the 
Electrocardiograph. This instrument is 
really a modified Einthoven galvanomet- 
er, consisting of a very powerful mag- 
netic field produced by an electromag- 
net and excited by a constant direct cur- 
rent, such as the current given by a stor- 
age battery. A very short air gap is made 
between the poles of the magnet and in 
this powerful field a fine quartz filament 
or fiber is stretched. Delicate adjusting 
means are provided for controlling the 
tension of this wire. (See Fig. 1.) 

A small diafram is placed on the center 
of this which closes two small holes that 
extend thru in each pole piece. These 
holes are the condensing microscopes and 
the projecting microscope to focus a fine 
beam of light to strike a moving photo- 
graphic film. If the wire is slightly dis- 
placed by the passage of an electric cur- 
rent thru it, it will naturally displace the 
small diafram and in turn permit the fine 
beam of light to pass thru the_ openings 
and strike the film placed opposite to the 
projecting lamp throwing out the fine beam 
of light. It will, therefore, be seen that 
by displacing the quartz wire in certain 
movements that a record will be made on 
the film accordingly. This quartz filament 
is connected to a Wheatstone bridge of 
proper dimensions and also to special 
terminals which are connected to the pa- 



tient whose heart is to be examined. These 
terminals are three in number and are 
made of German silver plates, each of 
them being fitted with binding posts con- 
nected to the leads, connecting the plates 
with the sensitive galvanometer and 
Wheatstone bridge circuit. 
Two of the plates are se- 
cured to the arms of the 
patient, while the third 
terminal is strapt around 
the left ankle. Proper 
care is taken to see that 
the electrical connection 
between the body and the 
terminal is of low resist- 
ance and for this purpose 
a wet cloth which is sat- 
urated with a 20 per cent 
salt solution is placed be- 
tween the foot and plate 
and again the cloth is 
wrapt about the plate. 
The Wheatstone bridge 
circuit is balanced so that 
the resistance of the elec- 
trical path between ter- 
minals is constant, and 
this is obtained when the 
quartz string or filament 
of the galvanometer is in 

a zero position. 

It is evident that a slight addition of 
current to the galvanometer circuit will 
cause a displacement af the filament, which 
is recorded on the film. Since the contrac- 
tion of the heart creates an- electric cur- 
rent as found by various scientists, and 
as the intensity of this current depends 



tN the present article we have one of the most interesting and startling 
revelations of what medical science, plus electricity, is doing to bring 
about a clearer understanding of our bodily actions. Herewith is pre- 
sented a true electrical record of a patient's heart, which shows the fluc- 
tuations occurring just before and at the critical moment when life ceased 
to exist. In other words, the patient died. 



upon the intensity of the heart contrac- 
tion, it is therefore obvious that the fine 
quartz wire will be displaced a certain 
amount by the generation of current by 
the heart. With the contraction wave, 
the electric potential spreads over the heart 
and thus the galvanometer records the 
heart beat and also indicates the origin 
and path by which the current spreads. 

An exact replica of the apparatus used 
in recording the pulsation of the heart is 
illustrated in Fig. 2. This shows the ap- 
paratus in actual use and also how the 
various electrodes are secured to the pa- 
tient. This photograph was taken at the 
time a record was actually being made of 
the condition of the patient's heart. The 
sensitive galvanometer is seen at the left, 
while the beam of light is derived from a 
powerful arc projector stationed at the ex- 
treme left, but not shown. The instrument 
at the extreme right is the photographic 
film apparatus. The film is driven at a 
definite and uniform speed ly an electric 
motor mounted at the bottom of the ma- 
chine. This instrument is placed in exact 
line with that of the telescope of the gal- 
vanometer pole-piece. The resistance box 
is shown on the shelf of the galvanometer 
table. 

The instrument traces its indication of 
conditions in the heart by curves on the 
photographic film. These heart pictures 



are as characteristic as finger prints or 
photographs. No '-'two individuals' hearts, 
beat alike, and the electrocardiograph, by 
its extremely delicate registration of the 
contraction of the muscle, readily shows 
the most minute difference. 

A remarkable story of a dying heart is 
told by the accompanying curves registered 
by the electroca diograph. The graphs il- 
lustrating this remarkable story are shown 
in the third figure, and these were taken 
by Dr. R. H. Halsey, of New York City. 

The records here reproduced form an 
almost complete electrocardiographic rec- 
ord of the heart b t during the last move- 
ments of the patient's life. Tho death 
was expected, yet its actual advent was 
much earlier than had been anticipated ; 
the transition from life to death was 
abrupt. The w ning of change is to be 
found in the lengthened conduction inter- 
val and in the changed ventricular com- 
plex of Fig. 5. That fibrillation of the 
ventricles was riot the immediate cause of 
death is clear from Fig. 6, taken when the 
usual signs of life were in abeyance ; the 
heart was profoundly affected, and the pa- 
tient past all possible hope of recovery 
before fi rillation ensued. 

The record was obtained from a female 
patient thirty yea s of age, suffering from 
broncho-pneumonia of both lower lobes. 
The curves were taken one after the other 
in quick succession and are described in 
this order. In Fig. 1 the frequency of the 
heart is 75. The duration of the diastole* 
varies from 0.2 sec, to less than 0.1 sec, 
and is non-rhythmic. The up-stroke of P 
is quicker than the downstroke. The con- 
duction time is within the 
normal limits of 0.2 sec. 
T is upward in its direc- 
tion and of considerable 
excursion. In the second 
figure, the frequency of 
the heart is 80. There are 
the same vibrations in the 
duration of the diastole. 
The electrocardiograph 
Figures 3, 4 and 5 show 
— __ _ the different frequencies 
of rne heart at different 
periods. In curve 5, 
the frequency of contraction of the heart 
appears to have dropt to 45, while asso- 
ciation of auricle and ventricle is still pres- 
ent. The conduction time is 0.4 sec. ; 
double the time in the earlier record. Dur- 




Close View ot the Einthoven String Gal- 
vanometer Used in Actually Measuring and 
Analyzing the Infinitesimal Electrical Cur- 
rents Produced by the Human Heart at 
Every Beat. Did You Know that Your 
Heart Was a Dynamo? (Fig. 1.) 

ing the very brief interval between the 
taking of Figs. 5 and 6, convulsive gasps 
and a slow contraction of the skeletal mus- 
cles oc curred. In Fig. 6, the change is re- 

* Diastole is the period of rest between con- 
tractions of the heart. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 








(Above) — Figures 1 to 4. 

markable, and the frequency of 
the ventricle has increased to 63 
per minute. The remaining com- 
plexes vary in their detailed form, 
but are similar in general outline. 
In Fig. 7, there are no evidences 
of coordinate ventricular contrac- 
tion. The remaining records are 
similar; in Fig. 13, all movement 
ceased permanently, the patient 
having died. 

When the heart takes a sudden 
jump to the fast rate, stops sud- 
denly and returns to the normal 
rate, a typical curve is made as in- 
dicated above. This condition is 
called a "flutter." The auricles of 
the heart sometimes contracting 
three hundred times a minute and 
the ventricles only one hundred 
and fifty times a minute ! 

By the use of the electrocardio- 
graph and a stethoscope connected 
with a microphone, the sounds 
made by the contractions of the 
heart are recorded with curves in- 
dicating the rhythm so that the 
exact point in the heart cycle of 
various normal and abnormal 
sounds may be recorded. 

Electrocardiograph records 
showing the action of the heart under cer- 
tain treatment may be made and sent to 
physicians in various parts of the world, 
who by interpreting the curves can ob- 
tain information of great value in the 
treatment of their own patients. 

In order to standardize such records, the 
tension of the galvanometer quartz wire is 
adjusted so that a current of one-thou- 
sandth of a volt will deflect the filament 
to such an extent that its shadow projected 
on the recording film will move one cen- 
timeter in both directions ! Since the wire 
is set to move a definite amount for a 
known voltage of current, the deflection 
shows the amount of current that caused 
it. The heart of the average individual 
causes a deflection which indicates the pas- 
sage of a current of approximately one to 
two one-thousandths of a volt. Thus it is 
known that it would require the heart 
beats of thousands of persons to generate 
enough current to light an incandescent 
lamp. 

In conclusion it may be said that the 
conditions of the human heart can now be 
studied with far greater accuracy than 
was ever possible heretofore, thanks to the 
Electrocardiograph. 



RADIUM AND 
CANCER. 

"The Other Side of 
the Radium Cure" is the 
title of an article by 
Dr. J. H. Blaisdell, in 
the Boston H erald. 
This is of such great 
interest that we give it 
below, as many of our 
readers have undoubted- 
ly read the recent re- 
port of the Director of 
the Crocker Cancer Re- 
search Commission 
printed in these col- 
umns. 

"Newspaper interpre- 
tation of medical sub- 
jects, vital to the inter- 
ests of the health of the 
community," says Dr. 
Blaisdell, "should be pe- 
culiarly conservative 
and well advised. To 
me your editorial com- 
ments on radium in can- 
cer on Wednesday 






(Above) — Figures 5 to 9. 

MAN SWALLOWED 
$20,400 WORTH OF 
RADIUM. 

In an article treating 
on the use of "Radium in 
Surgery and Gynecol- 
ogy" in Radium, Dr. 
John M. Lee relates a 
peculiar accident which 
haopened in applying a 
valuable tube of radium. 
Sarcomata and epithel- 
iomata of the tonsils in 
several patients have 
yielded excellent re- 
sults. In one of mv 
'first cases, a vigorous, 
powerful man, with 
more money than judg- 
ment, jerked his hea I 
backward thru the sup- 
porting hands of the 
nurse, and at the same 
time yanked the mucous- 
smeared and slippery 
braided silk thread out 
of my hand, just as I 
was about to seize the 
tubes in the pharynx 



morning of this week seem especially open 
to criticism on this score. 

"Briefly stated, your summing up of the 
findings of the Crocker cancer commission 
of Columbia University unqualifiedly placed 
radium in the discard as a 'cure,' damned 
it with faint praise as a palliative, and 
noted with the cheerful abandon of 'life 
opportunity given the medical profession to 
make 'the patient's condition worse than 
if he had been left alone.' Such- is the 
pessimistic side of the picture based on 
truth but, unfortunately for your readers, 
only half the truth. Simply because rad- 
ium cannot act as a 'cure' in inoperable 
or hopeless cases of systemic cancer is 
no reason why readers should be instructed 
to regard it as a discarded fad to the utter 
disregard of countless cases of early mal- 
ignant disease that this remedy has saved. 

"Point out rather to your readers (re- 
ferring to the editor of the Boston Her- 
ald ) the significance of the recent pur- 
chase of many thousand dollars' worth of 
radium by the -luntington Hospital of 
Boston, as an example of how useful it is 
in experienced hands. Tell them of its 
curative effects beyond that of any other 
remedy in epitheliomas or cancers 
of the skin. Lay your emphasis 
on how radium can absolutely 
prevent cancers of the skin if 
people could be taught to have the 
early pre-cancerous possibilities 
such as keratoses, warts, moles, 
etc., removed before degeneration 
starts. By such statements it 
seems to me you would be doing 
the greater services to the com- 
munity and more rightly interpre- 
ting the findings of the Crocker 
Cancer Commission on Radium." 



with forceps, and swallowed 175 
milligrams of radium in three 
well-screened tubes. He refused 
immediate gastrotomy, and the 
tubes were past thru the alimen- 
tary canal at the average rate of 
nine inches per hour. No injury 
followed and he said : "None of 
the crowned heads of Europe 
have anything over me in luxuri- 
ous repasts, for I have had the 
only distinction of the consump- 
tion of a $20,400 meal." 



(Below) — Figures 10 to 13. 




Tr R" 



/V~~~\f 



firm 



The Above Electrocardiograph Records, Numbered 1 to 13 Con- 
secutively, Represent the Most Remarkable Scientific Analysis 
of Just What Does Happen In a Person's Heart Shortly Before 
and at the Exact Period When Life Ceases to Exist, or Death. 
By Inspecting These Charts of the Heart's Variations During 
the Last Moments of the (Female) Patient, a Victim of Broncho- 
Pneumonia One Can See How the Heart Started to Fluctuate 
Progressively, Finally Stopping Action at the Right End. (Fig. 13.) i 



IO 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



Combating the Torpedo 



WAR after all is but a game of 
chess. The greatest generals 
of modern civilization realized 
this so profoundly that every 
one of them had been at one 
time a good chess player. In war, as in 
chess, luck plays but an insignificant part. 
Given like equipment, the general who has 
the greatest strategical ability will win, 
whether it be in the field or on the chess- 
board. Also, if both opponents can suf- 
ficiently anticipate each 
other's moves, no one will — — — — 
win. In this case there 
will be a stalemate, as it 
has existed for over two 
years in France. But 
stalemates necessarily al- 
ways denote equal strength 
of both opponents and a 
stalemate often turns out 
to be a negative victory, 
for it is certainly not de- 
feat. 

The present submarine —— — — — 
warfare is no exception 
to the rule of comparing 
war to chess, for the simple reason that it 
is an uneven game — all the powerful 
pieces are on the U-Boat's side and no 
Queen, Rooks and Knights on the other 
side of the board to defend the King. At 
least there was no defense worthy of the 
name up to a few months ago. 

But science, as always, is progressing 
steadily and soon the submarine will have 
found its master, or at least its equal, with 
which to stalemate it. 

Let me first correct a popular illusion. 
Almost every one of us thinks or speaks 
of the "deadly submarine," when, as a mat- 
ter of fact, the submarine itself is not only 
not deadly but a very weak contrivance at 
best. Point a 3-inch gun at it and it will 
vanish instantly. Send a 20-foot motor 
boat chaser against 
its periscope and the 
"deadly" submarine 
at once becomes 
deader than the pro- 
verbial doornail. 

It is the subma- 
rine's deadly weapon 
— t h e torpedo — that 
has so far out-gener- 
aled the cleverest 
brains and has given 
the greatest statesmen 
untold sleepless 
nights. To fight the 
submarine itself is 
comparatively easy, 
given good guns and 
good gunners on 
board the attackt 
ship, providing of 
course that the enemy 
submarine command- 
er is foolish enough 
to expose his craft too 
much above the 
waves. 

Several methods 
have been adopted of 
late to combat th? 
submarine, none of 
which have been 
great successes. 

First, we have the smoke-screen — per- 
haps one of the most effective schemes de- 
veloped lately. By means of dense vol- 
umes of chemical smoke, blown around the 
ship by powerful exhaust pumps, the ship 
is enveloped almost completely in a fog- 
like screen and it becomes a very difficult 
target for a torpedo. The ship's bow, how- 

This article appeared originally in the Sunday 
"New York American" of April 15t/i. 



By H. GERNSBACK 

ever, is nearly always exposed. The oth- 
er method is to protect the ship with 
strong torpedo netting suspended by means 
of booms from the ship. The torpedo upon 
striking the net is thus rendered harmless, 
as it never reaches the ship, unless the net- 
ting is made of rope and the torpedo is 
equipt with cutting blades. In that case 
the torpedo will strike the ship and blow 
it up. 

But the one great drawback of the net- 



OUR readers will find much food for thought in this interesting article. 
While the idea may not effectively stop enemy submarines from tor- 
pedoing every merchant vessel, we feel confident that we have shown 
a fairly practical way to obtain satisfactory results. 

Mr. Gernsback is donating his invention to the Nation and he wishes 
it to be understood that he will not require to be paid royalties or any 
other considerations from Amercian ship owners. Foreign ship owners 
are not included in the above. 



ting is that it is almost impossible to use it 
on a fast moving ship. It is too cumber- 
some and most important of all it greatly 
retards the speed of the ship, due to the 
excessive friction of the netting against the 
water. 

The next — and poorest — means to com- 
bat the submarine is our widely advertised 
mounting-guns-on-a-ship scheme. Xo sub- 
marine commander in his right senses ex- 
poses more than one or two feet of his 
periscope when making a torpedo attack. 
And remember no torpedo attack is ever 
made at a closer range than 800 yards. 
Two thousand, and even four thousand, 
yards are very common nowadays. Im- 
agine a gunner on even a slightly rolling 
ship trying to hit an object one foot high 




Patents Pending. 

Top View of Ship with its Ten "Motor-Torpedoes" Which Operate Independently from the 
Steamer. An Approaching Enemy Torpedo Is Blown Up or Thrown Off Its Course by Explod- 
ing One or More of the Little Motor-Torpedoes at the Critical Moment. Note that the 
Modern Torpedo Leaves the Submarine in a Curved Line After Which Its Gyroscope 
Rights It on the Final Straight Run. (Fig. 1.) 

and less than six inches in diameter, at a 
distance of 3,000 yards ! It simply can't 
be done. Scoring a hit under such cir- 
cumstances is pure chance, and don't for- 
get that the periscope itself does not stand 
still either. It, too, bobs up and down. In 
fact, at such a distance it is often almost 
invisible. 

Mounting guns on merchant vessels nev- 



ertheless is of distinct use, in so far as 
the guns will keep a submarine at a re- 
spectful distance and prevent the U-Boat 
commander from attacking the ship by 
means of his own gun-fire. But mounting 
guns on ships will never prevent a torpedo 
from finding its deadly mark. You can't 
shoot at a torpedo — the bullet is too small 
and the modern torpedo making 43 knots, 
i.e., 50 miles an hour, moves far too fast. 
After much thought on the subject, I 
came to the conclusion 
— that in the torpedo itself 
we have an effective 
weapon to combat the 
torpedo, strange as it 
may sound at first. You 
can combat a gun with 
another gun, and you can 
combat one rifle with an- 
other, as well as you can 
fight one aeroplane with 
another. 

Why not combat the 
—— — — — — — torpedo with another tor- 

™"^™*"" ™""^^~ pedo? It is all very pos- 
sible and simple if you 
know how ; as a matter of fact the idea 
struck me so favorably that I decided to 
apply for patents in all civilized countries. 

Several navy experts have reported fav- 
orably on the idea, and while up to this 
writing no ships have been equipt with the 
device, I would not be at all surprised to 
see the idea put into practise very shortly. 

Our front cover and the two accompa- 
nying drawings illustrate the idea clearly. 

The underlying idea of the whole scheme 
is that it takes the torpedo an appreciable 
length of time between the instant of be- 
ing released from its submarine and the 
moment it strikes the attacked ship. Tak- 
ing the closest range at which a torpedo 
can be fired as 800 yards — and it cannot be 
fired much closer successfully — this gives 
a time of 55/100th or 
over half a minute to 
cover that distance, 
short as it is. Tak- 
ing the average range 
of 2,000 yards, it will 
take the torpedo l 3 A 
minutes before it will 
strike. These figures 
are for the latest type 
Bliss-Leavitt torpedo 
making 43 knots, i.e., 
50 miles an hour. 

But a torpedo, 
whether it runs on 
the surface of the 
water or submerged 
below it, always leaves 
a very noticeable 
"wake" in its course. 
Remember a torpedo 
is propelled solely by 
comprest air, c o m- 
prest up to 2,200 lbs. 
per square inch. This 
air must of necessity 
come to the surface 
of the water, as the 
torpedo runs over its 
course. The disturb- 
ance created thus 
gives rise to the al- 
most snow-white wake, which is very no- 
ticeable from a distance. Thus a man sta- 
tioned on a ship readily sees the wake 
as it comes nearer and nearer and he 
can gage pretty accurately just where the 
torpedo will hit. ' Escape for the compara- 
tively slow-moving ship is impossible, even 
if the engines were reversed instantly. The 
vessel's momentum would still be so great 



May, 191 7 



THE ELECTRICAL EXPERIMENTER 



that the deadly torpedo would surely find 
its mark. 

My proposed means of rendering enemy 
torpedoes ineffective is as follows : Fig. 1 



sees to it that the speed of each torpedo 
keeps up exactly with the speed of the ship, 
for there should never be a drag on the 
cables. This is readily accomplished by 




Detonafing 
snitches 



Speed con 
trot ond 
reversing 
rheostat 



Volt and ammeters 
Snitches 

Cable reeling . 
drum A motor I 

1 

if* % 

Dec/r, 



Hoisting Davit 



Flexible cable to itiip 



Todynomo / 

Electric Coble to other 

mres torpedoes on* 

right side of ship 

Forward Most Torpedo 
Switchboard 



Explosive Charge 
Motor- Torpedo 



© 




Propeller motor 

Rudder control motor 



Rudders 
Propeller 



Concrete Ballasted tree/ 



means of rheostats, one for each torpedo. 
By cutting in more or less resistance the 12 
H.P. motor can be made to run faster or 
slower and the torpedoes are thus easily 
controlled as to speed. By means of a 
double-pole, double-throw switch the little 
l /2 H.P. motor is revolved in either direc- 
tion, thus effectively steering the little craft 
so that it will always keep at a distance 
of some fifty feet from the mother ship. 
On the control board furthermore there is 
a switch connected to a storage battery 
from which wires are run thru the cable 



PatentB Fending. 

Fig. 2. The Electrically Propelled and Electrically Steered Gernsback "Motor- Torpedo." It Is from 15 to 20 
Feet Long and Runs Independently from the Mother Ship. An Operator High Up on the Ship's Mast 
Blows Up the Motor-Torpedo by Electric Contact as Soon as the Enemy Torpedo Approaches Within 
15 Feet. Both Torpedoes are Thus Destroyed. 

shows the plan view of an average steamer, 
600 feet long. On each side we observe 
five (or more) independent, electrically 
propelled torpedoes. Fig. 2 shows the 
construction of the torpedo itself. Briefly, 
it is built along the shape of the regulation 
torpedo and measures from 15 to 20 feet 
in length and from 3 to 5 feet in diameter. 
It has a 12 horse-power electric motor 
geared to the propellers and there is also 
a little J/2 H.P. motor geared to the rudder 
with which to steer the torpedo. Most of 
the space between the war- 
head and the motors is taken 
up with the usual charge of 
gun-cotton. This torpedo, un- 
like its other brethren, has a 
heavily weighted keel to pre- 
vent it from rolling over, for 
reasons which will be appar- 
ent later. On the back of the 
torpedo is mounted a steel 
mast-like structure thru which 
the control cable passes. This 
cable then rui.s to the deck of 
the ship over pulley arrange- 
ments as shown in Fig. 2. 
There is also a drum to take 
up the slack of the cable, or 
to play out more cable should 
the occasion aris~. The cable 
then runs up on the mast into 
a special turret located as high 
up as is feasible. Here we 
find one or more operators 
sitting in front of the electric 
control-board. All the cables 
from the star-board side tor- 
pedoes run into the forward 
mast-turret, while all the 
cables from the port side tor- 
pedoes run into the rear mast- 
turret. Thus each set of op- 
erators watches out for the 
safety of his side of the ship. 

All of the torpedoes are 
painted in such a color that 
the operator can watch them 
readily and guide their indi- 
vidual course. Sitting at the 
control-board the operator 



into the torpedo and thence into the de- 
tonator placed in the gun-cotton charge, 
Fig. 2. Throwing this switch will blow 
up our torpedo. 

The war action of the idea 
is as follows : Our ship has 
left New York with all of the 
motor torpedoes hoisted out 
of the water and lashed se- 
curely to the decks. The mo- 
ment the need arises the tor- 
pedoes are lowered quickly 
into the water and the control 
operator starts the machinery 
of each torpedo, and in less 
than two minutes all of them 
should be running smoothly, 
fifty to seventy feet distant. 

Suddenly the outlook scan- 
ning the waters with his bi- 
noculars sights the periscope 
of an enemy submarine and 
in less than a minute later our 
operator observes the rapidly 
lengthening wake of a death- 
carrying enemy torpedo. 
High up as he is located, he 
calculates that in less than two 
minutes the enemy torpedo 
will strike somewhere between 
his motor torpedoes Nos. 1 
and 2 (see Fig. 1). By cut- 
ting in resistance into rheo- 
stat No. 1, he immediately 
slows up motor torpedo No. 1 
thereby intercepting the path 
of the enemy torpedo. Or if, 
for certain reasons, he wishes 
to use his motor torpedo No. 
2, he leaves No. 1 in its original course 
but by cutting out more resistance from 
rheostat No. 2, he speeds up the latter 
with the result that it advances faster than 
the ship and in this case as well it will 
intercept the course of the enemy torpedo. 

Suppose he decides to use motor torpedo 
No. 1. He has nearly two minutes to 
jockey it for position and he will find little 
trouble to intercept the course of the hos- 
tile engine of death. His eyes glued to 
the enemy torpedo (or to its wake), his 
{Continued on page 68) 




An Actual Photoqraoh of the "Wake" of a Modern Torpedo. 
Particular Torpedo Ran About 10 Feet Under Water, Having 



Photo by Paul Thompson. 

Attention Is Called to the Fact That This 
Been Fired by a Submerged Submarine. 



12 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



Sources of Electricity 



WtilLE most of us are familiar 
possibly with several sources 
of electrical energy, we do not 
always stop to think of the 
many possible sources which 
are little known, especially to the layman. 
We have endeavored in the present article, 
and with the aid of the accompanying full 
page illustration, to describe the principal 
known sources of electricity. 

Static Electricity : This form of elec- 
tricity is that which we see when we stroke 
pussy's fur in a dark room and obtain a 
spark when the hand is withdrawn from 
contact with the fur ; or again, we may 
obtain the same form of electric shock or 
discharge by rubbing together two dissimi- 
lar substances, such as a stick of sealing 
wax with a silk handkerchief, after which 
it will be found that the electrified stick of 
sealing wax will attract bits of paper or 
small pith balls. A rapidly moving belt oitcn 
develops a considerable amount of static 
or frictional electricity, which will tend to 
discharge to earth whenever possible. One 
may often stand near such a belt, and by 
holding the knuckles or even the ends of 
the fingers near the belt, a heavy static 
discharge will take place between the belt 
and the fingers, the electric charge passing 
thru the body to earth. 

One. of the usual and practical sources 
of such electricity is the static machine 
(Fig. 1) and when the handle of such a 
machine is turned, one or more insulating 
discs are rapidly rotated, and by succes- 
sive intensification of a very slight electric 
charge existing on the tin-foil sectors of 
these plates before the machine is started 
up, a surprisingly powerful static discharge 
is rapidly built up. This will manifest 
itself in the form of an electric spark, 
which crashes across the gap between two 
metal balls on the side of the machine. 
There are many other sources of static 
electricity but the whole phenomenon is 
practically the same. 

Contact Electricity : It was Volta who 
showed that the contact of two dissimilar 
metals in the air produce opposite kinds of 
electrification, one becoming positively, and 
the other negatively electrified. There has 
been considerable discussion as to the exact 
action occuring in the production of elec- 
trical currents by the contact of two dis- 
similiar methods in air, and for a long 
time, says Silvanus P. Thompson, the ex- 
istence of this electrification by contact was 
denied, or rather it was declared to be due 
(when occurring in voltaic combinations) 
to chemical actions going on ; whereas, the 
real truth is that the electricity of contact 
and the chemical action are both due to 
transfers of electrons between the sub- 
stances under the peculiar actions of forces, 
about which very little is known with cer- 
tainty as yet. 

Volta found that the difference of elec- 
tric potential between the different pairs of 
metals was not all equal, as while zinc 
and lead were respectively positive and neg- 
ative to a slight degree ; zinc and silver 
proved to be positive and negative to a 
much greater degree. The voltage ob- 
tained by the contact between zinc and 
carbon is 1.09 volts. 

The phenomena of electrical currents 
produced by the contact of dissimilar 
methods is illustrated by Fig. 2. A dif- 
ference of potential or voltage is also pro- 
duced by the contact of two dissimilar 
liquids. It has been found that a liquid 
and a metal in contact exhibit a difference 
of potential or voltage, and if the metal 
tends to dissolve into the liquid chemical, 
there will be an electro-motive force acting 
from the metal toward the liquid. A hot 



metal placed in contact with a cold piece 
of the same metal, also produces a differ- 
ence of potential, and lastly Sir Joseph J. 
Thomson has demonstrated that the sur- 
face of contact between two non-conduct- 
ing substances, such as sealing wax and 
glass, is the seat of a permanent difference 
of potential. 

Galvanic Electricity : The primary bat- 
tery is generally denned as one in which 
electrical energy is produced by chemical 
means, without having to charge the battery 
from dynamo or other source originally. 
The simplest form of such a battery com- 
prises a glass or other vessel containing 
sulfuric acid and water, or any other oxi- 
dizing acid solution, and in which are im- 
mersed two clean metal strips, one of zinc 
and one of copper. Most of us are prob- 
ably familiar with the common form of 
primary battery used in American prac- 
tise for ringing bells and operating medi- 
cal coils in the form of the well-known 
dry cell, or with the zinc-copper-salam- 
moniac cell. In the zinc-copper-acid cell 
above mentioned, a continuous flow of 
electricity may take place thru a wire or 
apparatus which connects the two plates. 
When such a current passes, the zinc strip 
may be seen to waste away, or decompose 
by the electro-chemical action taking place, 
and its consumption, in fact, furnishes the 
energy required to drive the current thru 
the cell and the connecting wire or ap- 
paratus. In such a cell, the zinc strip 
forms the positive electrode or negative 
terminal, while the copper -strip forms the 
negative electrode or positive terminal. 
Such a cell gives about one volt potential. 

Fig. 3 shows a unique form of primary 
battery known as the Hauck Circulation 
battery. In this battery, composed of sev- 
eral cells, the electrolyte or solution is 
caused to pass from a tank above the bat- 
tery cells, thence thru the first or higher 
cell, then thru the next lower container, etc 
This is a chromic acid battery with car- 
bon and zinc electrodes. The zincs are lo- 
cated in the rectangular porous cups while 
the two carbon plates are outside of the 
porous cups, all the space between porous 
cup and carbon plates, as well as between 
the carbon plates and glass vessel being 
filled out with small carbon pieces. In the 
porous cup there is a sulfuric acid electro- 
lyte, while the carbons stand in chromic 
acid. As the latter is caused to circu- 
late continuously from one battery to the 
next, all polarisation is done away with 
and we obtain a very steady and powerful 
current. The battery illustrated gives 6 
volts and 60 amperes and can be used to 
charge storage batteries, run fans, or elec- 
tric lamps. It is one of the best chromic 
acid batteries ever designed. 

Electricity from Gases : Fig. 4 shows the 
famous Grove Gas Battery invented in l£39. 
It shows how two gases are used to pro- 
duce an electric current. The two glass 
tubes contain platinum strips coated with 
spongy platinum. The glass bottle contains 
acidulated water in which the two glass 
tubes plunge, as seen. One of the tubes 
contains oxygen, the other hydrogen, as 
will be noted the gases make contact with 
the acidulated water. If we connect the 
two terminals with a galvanometer we will 
observe an electric current, the oxygen fur- 
nishing the positive, the hydrogen the nega- 
tive pole of the battery. Incidently we 
note that, as we consume current, the liquid 
rises in the two glass tubes, but twice as 
fast in the hydrogen tube as in the one 
containing the oxygen. As each tube is 
identical with the other, except for the 
gases, it follows that the current can be 
due only to the gases. Also different gases 



produce different voltages and currents. 

Pyro -Electricity or Electricity from Crys- 
tals : In the accompanying Fig. 5, we have 
several methods by which minute quantities 
of electricity are produced from crystals, 
when these are manipulated in a specific 
manner. Certain crystals, when they are 
heated or cooled, exhibit electrical charges 
at certain regions or poles, and such crys- 
tals which become electrified by heating or 
cooling are said to be pyro-electric. One 
of the principal crystals which manifest 
this peculiar action is tourmaline. The 
tourmaline has been cited in history, and 
is mentioned by Theophrastus and Pliny 
under the name of Lapis . Lyncurius . The 
tourmaline possesses the power of polariz- 
ing light, and is usually found in slightly 
irregular three-sided prisms which, when 
perfect, are pointed at both ends. It is in- 
teresting to note that in heating such a 
crystal as the tourmaline, it attracts light 
pith balls to its ends when electrified. If 
the temperature is kept steady, then no 
such electrical effects are observed either 
at high or low temperatures, and again 
the phenomenon ceases altogether if the 
crystal is warmed above 150° C. If a 
heated crystal of tourmaline is suspended 
by a silk fiber, it will be attracted and re- 
pelled by electrified bodies or by a second 
heated tourmaline. Among other crystals 
which belong in the pyro-electric family 
are silicate of zinc, boracite, cane sugar, 
quartz, tartrate of potash and sulfate of 
quinine. 

Electricity is produced by the disruption 
and cleavage of certain substances, as for 
instance, when a sheet of mica is split 
apart, which action is usually accompanied 
by the production of a number of sparks, 
and both laminae are found to be elec- 
trified. If sulfur is fused in a glass dish 
and allowed to cool, it becomes powerfully 
electrified, which action may be tested by 
lifting out the crystalline mass with a 
glass rod. Chocolate is another substance 
which manifests such an electrification 
while becoming solidified. 

Piezo-Elcctricity is the term given to 
that form of electrical energy produced 
when certain crystals are placed under pres- 
sure in a certain direction. With respect 
to the make-up of the crystal, it was found 
that if a crystal of calspar was prest be- 
tween the fingers so as to compress it along 
the blunt edges of the crystal, that it be- 
comes electrified, and retains its electrical 
charge for some days. This phenomenon 
is believed to be due in certain crystals to 
what is known technically as skew-sym- 
metry or hemihedry in their molecular 
structure. 

Thermo-electricity: If we take two 
metal bars, one of bismuth and one of 
antimony, and join these together, it will 
be found that an electric current is pro- 
duced of an appreciable magnitude when 
the juncture between the metals is heated 
in the flame of a candle or other source 
of heat. To demonstrate that there is an 
electric current produced in all such cases, 
it is but necessary to connect a sensitive 
electric current-detecting device, such as a 
galvanometer to the free ends of the bis- 
muth-antimony couple, as it is called. If 
all parts of the circuit, including all sec- 
tions of the bismuth-antimony couple, are 
at one temperature, there will be no cur- 
rent produced, since the electro-motive 
forces are in perfect equilibrium. How- 
ever, when a junction between two such 
metals is heated, this equilibrium of the 
electrons and molecules no longer exists, 
and gives way to the production of an 
E.M.F. or difference of potential. 

(Continued on page 71) 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



13 



SOURCES OF ELECTRICITY 




{For description see opposite page.) 



14 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



Magnetism Produces Remarkable Photographs 



WHAT causes iron, a dense, 
heavy substance, to ignore or 
overcome the laws of gravity 
and to dart thru space to a 
magnet? What is this mys- 
sterious, so called, attraction? Can this 
swift and sure motion of a heavy body 
thru space be caused by lines of force with- 
out motion, by lines of tension in ether or 



BY F. F. MACE 
Superintendent of Public Schools, Pecos, Texas 

sistent with the laws of nature, for all the 
facts of magnetism. Jk 

But even this was not sufficient. The 
facts of nature had been distorted for 
years. These experiments, conclusive as 
they were, might be distorted and thrown 
aside. It must be proven beyond a shadow 
of doubt in some striking manner that 
there are actually currents about the mag- 



of vibration, be such as to effect the pho- 
tographic plate? I could only try it, as 
I had tried other things, and hope to obtain 
the result sought. 

The result justified the hope. Taking 
every precaution known to a photographer 
to prevent the result being effected by light 
or other influences I exposed a plate on 
which were placed a number of objects 




Fig. 2. Photograph Taken in Usual Manner, 
Showing the Various Objects "Magneto- 
graphed." 

by mere lines of direction, like lines of lati- 
tude or longitude? Can these lines of 
force tending or extending, moving with- 
out motion from one pole to the other, 
or lines of force or .tension "emerg- 
ing," without motion, from one pole and 
"entering," without motion, the other pole, 
produce the same result at both poles? 
Can any possible arrangement of the 
molecules of the magnet, supposing this 
arrangement to be brought about, possibly 
extend thru space and accomplish this 
result? Can any or all of these mir- 
acles, these things themselves contradic- 
tions of the known laws of nature, bring 
about another miracle — a result oppos- 
ing, apparently, one of the laws of na- 
ture? Is there a cause for these things 
in keeping with the known laws of na- 
ture? 

These questions presented themselves 
when I first studied physics. They 
asked themselves more insistently when 
I began to teach physics, and they have 
been reiterated again and again in vary- 
ing form by every class of beginners 
whom I have appeared before. For 
more than fifteen years I sought to ob- 
tain an answer, a true answer, to these 
questions — an answer which would really 
account for the facts and which would 
be in accord with the other known laws 
of nature. For years only a faint glim- 
mering of the truth appeared. Then 
gradually the light grew stronger until I 
had worked out a clear and logical an- 
swer. But to answer these questions by 
pure logic based on the known facts of 
nature was not sufficient. Modern 
science demands experiment; tho New- 
ton and Galileo, and Leplace never per- 
formed an experiment but based their 
discoveries on the facts before them. 
Therefore, I worked patiently for years 
to demonstrate in a new way that which 
I knew to be true, until I had proven by 
experiment, that which I had proven by 
logical deduction, that the attraction of 
the magnet and all of the phenomena of 
magnetism are produced by the motion 
of ether currents about and thru the 
magnet, and until I was able to demon- 
strate the cause, nature, and direction 
these currents, and by the direction 
these currents to account logically, con- 



Fig. 3. Here We See the Best "Magneto- 
graph" of the Objects in Fig. 2; It Was Made 
In a Vacuum. 

net — that there is motion. How could this 
be done? I had worked with photography 
for years and was familiar with the X-ray. 
While pondering this situation the thought 
occurred to me : will the photographic 
plate — a photographic plate in a vacuum — 
prove this? A photographic plate is only 
affected by motion ; by light, which is ether 
motion; by chemical action, which is mole- 
cular motion ; by heat, which is molecular 
motion ; and by the X-ray, which is in 




of 

of 



ig. 1. How the Author Arranged the Objects to 
e Photographed by a Magnet, Placing Them on 
Photo Plate Under the Bell of a Vacuum Pump, 
Permitting the Air to Be Exhausted. 

motion. Even granting the ether currents 
about the magnet as I had proven them to 
exist, would their wave length, their rate 



Fig. 4. Exposure of Photo Plate and Vari- 
ous Objects Placed Over a Magnet Under 
Atmospheric Pressure. Compare with Fig. 3. 

under an exhausted receiver. At the end 
of three days I removed and developed the 
plate. Images were there, faint but un- 
mistakable. The experiment was a success ! 
I am sorry that I afterwards dropt and 
broke this first plate while attempting to 
handle it during a spell of illness. 

With certain success before me I took 
every precaution to render the result be- 
yond question. In a dark room from which 
every ray of light was excluded, using only 
_ a perfectly safe ruby light, I placed ob- 
jects on a common photographic plate 
and placed them under the receiver of 
an air pump as shown in Fig. 1. These 
articles are shown in Fig. 2, as they 
appear when photographed with an or- 
dinary camera. "A" is a lead ring or 
washer. "B" and "C" are metric 
weights. "D" is a piece of gasket rub- 
ber. "E" is a broken metal buckle. 
"F" is a bone button. "G" is a scrap 
of acid-eaten zinc. "H" is a wooden 
button. "J" is a piece of sealing wax. 
"K" is a lump of resin. The magnet 
used 'is an ordinary steel U-magnet, 
weighing one kilogram (or 2.2 lbs.). 
The • msitive side of the plate is above 
and the objects lie on the sensitive side. 

After the objects were placed on the 
plate under the receiver, twelve thick- 
nesses of black cloth were placed over 
the receiver and the air was exhausted. 
Then over all of this was placed a light- 
tight box and the .whole was finally 
wrapt in ten thicknesses of black cloth. 
The ruby light was then removed from 
the room and the room was locked and 
not reopened for twenty days. I may 
add that the whole operation took place 
after nightfall. 

At the end of twenty days the room 
was entered after dark and the plate 
was taken from the receiver and de- 
veloped by ruby light as with an ordin- 
ary photograph. The result is shown in 
Fig. 3. The articles are lettered to 
correspond to Fig. 2. The one marked 
"D" was lost and is not included in 
Fig. 2. 

Here is incontestable proof that there 
is motion, that there are currents, about a 
magnet. No mere line of force, no ten- 
sion in ether, no mere line of direction 
(Continued on page 70) 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



The Therapy of Light and the New "R-Ray" 

By H. ROSENTHAL 



THE therapeutic use of light has 
been known for ages ; in fact, it 
belongs to a period so remote 
that we are unable to determine 
even approximately the time of 
its introduction as a healing agent. 

In the far East the earliest writings men- 
tion the use of light in the cure of disease, 
and in the comparatively more recent rec- 
ords of Central American aborigines we 




Fig. 1. Appearance of Special Electric Arc 
Devised for Producing the "R-Ray" Radia- 
tions, Which Have Proven Extremely Satis- 
factory in Light Therapy Treatment for 
Certain Diseases and Ailments. 

find accounts of miraculous cures per- 
formed by the Sun God. Even at the time 
of our early pioneers on this continent 
there are authentic reports of a custom 
practised by many Indian tribes, who treat- 
ed wounds and pulmonary afflictions, rheu- 
matism, neuralgia, et cetera, by exposing 
the naked skin to the mid-day sun, allowing 
the rays to fall directly on the part af- 
flicted. This custom was in vogue ages 
before the Spanish Conquest, and was com- 
mon among the aborigines of America, 
from Yucatan to the Arctic Sea. 

We have, therefore, historic proof that 
light rays have been used from time imme- 
morial in the treatment of disease, and 
while modern science and modern meth- 
ods have attained the same ends, they have 
not changed the principles known to primi- 
tive man — but have merely developed the 
art. 

As light rays are the oldest and most 
universally accepted 
therapeutic agent, we _ 
naturally ask — how 
are they translated 
into terms of therapy 
by the human body? 
To which the answer 
is, thru the medium 
of vibration and pene- 
trative force of quan- 
tity. 

Light and electrical 
radiations are both 
waves that are pro- 
jected thru space at 
the same velocity. 
They are identical in nature, tho one 
wave length or radiation may differ 
from another, the same as one sound 
wave may vary in length from an- 
other, as found in the various tones 
or vibrations of music. Yet all wave 
lengths, whether light or sound, pro- 
duce their own corresponding vibrations 
and we therefore recognize all such vibra- 
tions in terms of light or sound. 

Tn further proof of this existing vi- 
bratory theory we have color, which in 
reality exists only in the mind, for color 



value is dependent solely upon the number 
of vibrations impinging upon the retina 
of the human eye. As for instance when 
the retina is stimulated by a vibratory 
force that approximates 400 trillions per 
second, the impression produced upon the 
brain is that of the color red; 750 trillion 
vibrations per second is interpreted by the 
brain as the color violet. And so on thru 
the scale of our visible spectrum. Yet, 
were the human retina sufficiently sensitive 
to receive and distinguish the 
many intermediate vibrations, 
it would perceive, thru the 
brain countless millions of tints 
and numerous values that lie 
between these two extremes. 

When these countless mill- 
ions of tints are all combined 
we see only white. And tho 
we perceive and interpret white 
light as being white, still we 
know that it is not white, but 
the combined primary colors 
and their countless intermedi- 
ate tints. This fact is easily 
proved by simply passing a 
beam of white light thru a 
prism, which will show the 
primary colors making up the 
white beam. 

Light vibration without penetration, force 
or quantity is in itself therapeutically neg- 
ligible. To have force, it should be direct, 
and to have penetration the source and 
quantity should furnish vibrations of prac- 
tically uninterrupted intensity. 

One source of light which fulfills the 
above conditions is our own sunlight, which 
penetrates every portion of the human body 
and exerts a most powerful influence on 
its economy by oxygenating the blood, gen- 
erating hemoglobin and producing red cor- 
puscles. And when we Lecome Sun- 
Dodgers we cannot expect any other phy- 
sical condition than that which takes place 
in plants under like circumstances, and 
which entails on human beings the neces- 
sity of resorting to other means for making 
up the deficiency — generally drugs. 

Summing up therefore the laws that gov- 
ern the therapy of light, we find it has the 
same relation to chemical actions which 
are governed by the chemic response set up 
in the substance or tissue, and not by the 
inherent quality of the ray; while all phy- 
sical conditions are secured in direct ratio 
to the penetrative power, quantity and vi- 



in a given interval. So that from a ther- 
apeutic standpoint it is always highly im- 
portant to have at our command as great 
a number of these vibrations as possible; 
i.e., of the oscillatons. It has been averred 
by the medical profession that each and 
every corpuscle and cellular structure in 
the human body is composed of an infinite 
number of delicate receivers, each of which 
respond only when the right tune or vibra- 
tion strikes them. Thus when given ma- 




S3 

"0 I 



^- K <0 <n <t M 



tUCTWC 

OSCILLATIONS 

FROM 



STORM 
IN SUN 



-13 



ELECTRIC 
OSCILLATIONS - 



IN SMALL SPHERES 



UK MAPT 



Fig. 2. Chart Showing the Position Occupied by the New "R-Ray" in the Soectrum, 
Including the Relative Position of the X-Ray Vibrations and Ultra-Violet Rays. 

4, 503, 599,627. 370,496 = Ultra violet photog. in vacuo 

789.000,000,000.000 = Violet end of visible spectrum 

.562,949,953.421,312 = Green light 

451,000,000,000,000 = Red end of spectrum 

281,474,976,710.656 = In f ra-red 

70,368.744,177,664 = Heat rays of solar spectrum 

47,000,000,000 = Electric oscillations in small spheres 

Oncein 4.7 seconds = Eiectiicoscillationstrom storm in sun 

brating quality of the light employed. 

All light waves possess two main charac- 
teristics that differentiate the effect pro- 
duced namely: first, the number of vibra- 
tions in a given interval of time, and sec- 
ond, the length of each oscillation or wave 



Fig. 3. Spectrogram of the New "R-Ray," Showing Clearly 
Its Great Range in the Field of Light Therapy, Extending 
as It Does Beyond the Visible Spectrum. 

jor, minor and chromatic scales to operate 
with, the skilled therapist can compel the 
brations of any cellular structure to re- 
spond to those which are produced arti- 
ficially ; and call into action complete ther- 
apeutic results, just as in music we call in- 
to play the various graduations of tone and 
produce perfect harmony. 

The period of vibration or oscillations 
which make up light waves and which the 
human eye will respond to, are those above 
the infra-red rays or heat rays and those 
below the ultra-violet or invisible light rays. 
The difference between the two is that the 
vibration of the infra-red is very small and 
the wave length very long, while those of 
the ultra-violet region have a tremendous 
period of vibration and a very short wave 
length. 

The therapeutical work that has been 
conducted points to the fact that the ultra- 
violet rays are most advantageous and con- 
sequently of greatest use in light therapy. 

We know that light rays from such 
sources as the Finsen, Minin. Ultra-violet 
and X-ray are each capable of exciting a 
normal, subnormal or abnormal human re- 
ceiver. 

However, our sci- 
entists not being sat- 
isfied with the belief 
of the existence of 
another source of vi- 
bration beyond the 
ultra-violet region, 
took another step in 
this direction which 
proved to be success- 
ful, inasmuch as they 
have found a region 
between the extrem- 
ity of the ultra-violet 
and the beginning of 
the X-rays. The re- 
gion is still unexplored, but there is 
little doubt that the greatest thera- 
peutic secrets lie hidden there. 

It is believed that we are only be- 
ginning to learn of the real benefits 
to be gained by the scientific applica- 
tion of light rays by skilled therapists. 
The author, who has been engaged in 
this, as well as the electrical field of re- 
search for many years, discovered a new 
ray which he has christened the R- 
ray. The production of this new source of 
(Continued on page 47) 



W<fVE 
T N' 



LE icvns 

METEI1S 



dCTAVEi 



1 6 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



Powerful Electro =Magnets Perform the Work of Many Men 



The ordinary work of a man loading 
pig iron from the ground upon a railway 
car was from 12 to 13 tons per day. The 




The Crucible Steel Company Have in Use at Their 
Pittsburgh Plant This Gigantic 62-inch Electro- 
magnet. It Can Lift 4'/ 2 Tons of Steel Bars and the 
Trip of a Switch Releases the Entire Load Instant- 
ly. This Class of Work Spells "Economy" in Big 
Letters and Foundries Everywhere Are Rapidly 
Awakening to the Fact. 



lifting magnet, however, nas rendered it 
unnecessary for this laborious work to be 
performed by human effort, and the re- 
sults, as given in the unloading of the 
steamer, Erwin L. Fisher, at Indiana Har- 
bor, Ind., are given in brief below : 

With a cargo of 4,000,000 pounds of pig 
iron, the time required to unload this ves- 
sel with twenty-eight men was two days 
and two nights, which corresponds to about 
3,000 pounds per man per hour, or about 15 
tons per day of ten hours. When the 
lifting magnet was introduced, the total 
time required for unloading was reduced 
to eleven hours and was done by two men, 
whose labor consisted in manipulating the 
controllers in the cages of the cranes. Thus 
two men and two magnets duplicated the 
work of twenty-eight men in less than one- 
fourth the time. Under these conditions 
the handling capacity of a man and a mag- 
net was nearly one thousand tons in eleven 
hours, or about 900 tons per day of 10 
hours. This is fifty times as much as was 
accomplished by hand labor, or twenty 
times as much as is possible even under 
scientifically managed manual labor. Fur- 
thermore, the operation was chargeable 
with less than one-fourth the overhead 
charges, while the vessels were enabled to 
double their number of productive trips. 

The lifting magnet has been adapted for 
the handling of materials in all branches 
of the iron and steel industry. It is used 
for handling pig iron, scrap, castings, bil- 
lets, tubes, rails, plates, crop ends ; for load- 
ing and unloading cars and vessels, and for 
handling skull-cracker balls and miscella- 
neous magnetic material. In fact it seems 
to be axiomatic that wherever magnetic 
material, and especially raw material, is to 
be handled in any considerable quantity, a 
lifting magnet can be used to advantage 
and will be a profitable investment. 

The accompanying illustration shows in 



a marked manner the practical application 
and efficiency of iarge electro-magnets used 
industrially. The first illustration shows a 
gigantic electro-magnet measuring 
62 inches in diameter and swung 
from a crane at 'the plant of the 
Crucible Steel Company at Pitts- 
burgh. This mighty magnet has 
been photographed in the act of lift- 
ing 17 steel billets, each weighing 
575 lbs., or a total of 8,925. It takes 
but a moment's reflection to readily 
conceive just how much man-power 
would be required to move this 
same weight of steel, not to men- 
tion the time occupied in moving it. 
A single operator, in this case the 
man operating the crane, lowers the 
magnet onto the steel bars and when 
in contact or nearly so, he closes the 
switch supplying the magnet with 
electric current. The magnet in- 
stantly becomes alive and exerts 
several tons of magnetic tractive 
power and holds the billets to its 
face securely, as pictured in the il- 
lustration. The crane may swing 
along for several hundred feet, car- 
rying its suspended load, and as 
soon as it reaches the desired loca- 
tion the magnet is lowered; when 
the operator opens the switch the 
magnet instantly releases its tons 
of steel. 

The second illustration shows a 
powerful electro-magnet at work in 
the yards of the Chicago, Milwau- 
kee and St. Paul Railroad's West 
Milwaukee shop, the magnet meas- 
uring 43 inches in diameter and lift- 
ing in this case a locomotive drive 
wheel. The lifting magnet is an at- 
tractive proposition to-day and not 
only appeals in large sizes but in the very 
small sizes as well. The small hand type 
electro-magnet is particularly efficacious .for 
picking up quantities of iron nails, screws, 
etc., in hardware stores and stock rooms 
and finds application in a thousand and one 
different ways daily. 




THE ELECTRIC HEATER FOR THE 
KITCHEN BOILER. 

The accompanying semi-sectional view 
of an ordinary kitchen boiler shows how 
a recently perfected electric water heater 
is attached to it. This heater heats the 
water before you turn the faucet and not 
■ — some time afterward. The tank is always 
charged with scalding water at any tem- 
perature you wish 
up to 2 00° F. 
(212 F. boiling 
point), or enough 
heat for about 
five baths — always 
on tap. 

The heater has 
six steps — and the 
regulator is a six- 
point current con- 
trol. When no 
water is being 
drawn the heater 
will probably be 
cut entirely out so 
that no electricity 
is being used. 
Then as some 
water is drawn 
the. regulator picks 
out that step of 
the heater which 
will pump back 
into the boiler the 
same amount of 
heat that is drawn 
from the faucet 
in the hot water. 
At the sixth step 
the regulator ap- 
plies two full 
horsepower, stor- 
ing heat at 100% 
efficiency. It is claimed that this partic- 
ular electric water heater will operate on 
15 to 20 per cent less energy than the cir- 
culation type heater, for the same monthly 
gallon production. 

The present heater has been specially de- 
signed to make it self-cleaning. Under 
tne intermittent operation of the thermal 
control there appears a slight but constant 
opening and closing of the split heating 
tube, which readily cracks off all scale and 
any precipitate forming on the tube. This 
deposit accumulating at the base of the 
heater is then easily flushed out of the full 
size 1 '4-inch drain. This self-cleaning 
feature is, perhaps, next to efficiency in im- 
portance to the housewife to whom a 
burned-out heater means not only needless 
expense but several days' interruption in 
the hot water service and a recent engineer- 
ing report gives the external circulation 
type water heater four months in which to 
become absolutely choked with scale. 




An Electric Heating 
Unit That Fits the 
Kitchen Boiler. 



43-inch Magnet Lifting a Lecomotive Drive 
Wheel at the West Milwaukee Shop of the 
C. M. & St. Paul Railway. Another Instance 
of What the Lifting Magnet Is Capable of 
Doing. 



CAN SINK SUBMARINES BY 
WIRELESS, SAYS INVENTOR. 

Theodore Eichholz,. a young engineer 
and architect of Pittsburgh, has invented a 
wireless device that may be used to destroy 
submarines by causing an explosion of 
gases that are always present in submer- 
sibles, he claims. For several years the in- 
ventor was connected with the United 
States Corps of Engineers. 

Mr. Eichholz stated that just recently 
a small experimental apparatus in his home 
on Neville Island sunk a small "dummy" 
submarine in the Ohio River, five miles 
away. The destroyed model was of steel 
and submerged to a depth of ten feet. 

All submarines while under water are 
propelled by electric storage batteries 
which throw off a gas that pervades the 
hull. This gas, Eichholz says, he detonates 
by the wireless current and destruction 
follows. The apparatus will be submitted 
to the U.S. Government at once. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



17 



NOVEL TELEGRAPH INSTRU- 
MENT THAT RESPONDS TO 
VOICE. 

Strange as the title may seem, yet the 
successful operation of such a device has 
been accomplished thru the researches of 
Mr. Christian Berger of New York City. 

The accompanying photograph shows the 
complete equipment of the electric voice- 
operated telegraph instrument. The opera- 
tion of the device is not attained by the 
employment of a microphone of any kind, 
but by means of a sensitive sound-oper- 
ated circuit-breaker, which controls a spe- 
cial relay and which in turn operates elec- 
trically either a sounder or recording in- 
strument. The circuit-breaker is placed in 
a metal box which is seen in the center 
background of the photograph. This con- 
sists of a bent wire, properly balanced on 
an insulating block. The end of this wire 
presses lightly against the side of the box-, 
which makes a permanent contact when it 
is not disturbed. The second connection 
is made thru the metal box and this is ter- 
minated with one binding post of a bat- 
tery, while the bent wire is connected to one 
side of the relay electro-magnet, the op- 
posite side being linked to the other bind- 
ing post of the battery. The electro-mag- 
net actuates an armature which controls 
a cog-wheel by means of a projecting strip 
on the armature. On the same shaft with 
the cog-wheel is a drum upon which a 
number of contacts are secured. These are 
alternately connected, so that one will com- 
plete the electrical circuit when desired 
and when moved to the next stud, the cir- 
cuit will be opened. It is built on the lines 
of a step-by-step relay, which has been 
used some years ago for controlling mov- 
ing vessels by radio waves. The drum cir- 
cuit and the horizontal brushes which touch 
the drum studs, are connected in series 
with the recording instrument and battery. 

The operation of the apparatus is ex- 
ceedingly simple as one must only be fa- 
miliar with the telegraph code, but not 
experienced in handling a telegraph key, 
as the transmitting is done by calling out 
the dot and dashes to the instrument. 
When a signal is made the sensitive sound 
actuated circuit-breaker opens the circuit 
which causes the armature of the relay to 
release it, thus giving a rotary motion to 
the cogwheel and in turn closing the re- 
cording instrument circuit. The complete 
equipment is very interesting when in ac- 
tion and possesses many diversified possi- 
bilities. 



LOS ANGELES HAS WONDERFUL 
ELECTRIC FIRE TRUCK. 

THE electric equipment of a new 
fire-fighting apparatus recently 
built by the Los Angeles fire de- 
partment has no equal in the 
country. This equipment is 
mounted on a ton and a half motor truck 



As a precaution against any one accident- 
ally touching the foot throttle and speeding 
up the engine to too great a speed, when 
the wagon is standing at a fire, a special 
protective device has been provided, which 
consists of a hood which can be lowered 
and locked in a position, completely pro- 
tecting the foot throttle from the curious. 




Los Angeles, Cal., Boasts of Having One of the Most Complete Electric Fire-fighting Trucks 
in the United States. The Equipment Comprises Five Powerful Searchlights Which Are 
Supplied with Power from Either a Large Storage Battery or the Dynamo Shown in the 

Picture. 




Speak to This Telegraphic Novelty and It Recor 
alent Dots and Dashes on a Paper T 



ICELAND'S ELECTRICAL PAPER. 

Elcktron is the name of an electrical 
magazine publisht monthly at Reykjavik, 
Iceland. The leading article is on the Ice- 
landic telegraphs and telephones, by Mr. 
Gisli J. Olafsen, who visited this country 
a year or more ago and studied American 
telegraph and telephone methods. This ar- 
ticle is printed in the Danish and English 
languages. 



and was both designed and built by mem- 
bers of the fire department. 

The equipment consists of five powerful 
searchlights, each rated at 250 watts, capa- 
ble of throwing a brilliant beam of liglit 
over 500 feet away. At this distance work 
at a fire can be carried on with great effi- 
ciency. Yet these lights are so arranged 
with diffusing lenses that it does not blind 
the firemen, even a few feet away. 

The lights are 16 inches in diameter. 

Three are permanent and 
two are portable, each be- 
ing attached to 320 feet of 
heavily insulated cable 
wound on a reel which can 
be unrolled, permitting the 
lights to be carried this 
distance into a burning 
building. 

The handicap of a strange 
and smoky building is over- 
come by the use of these 
portable lights. They will 
penetrate smoke to almost 
an unbelievable distance, 
permitting the firemen to 
fight fires thru dense smoke 
with the greatest of ease. 
Power is received from eight large stor- 
age batteries placed behind the seat. These 
batteries themselves are capable of furnish- 
ing current for the lights for seven hours. 
Also installed on the right foot-board is 
a generator of 50 amperes, 25 volts, 1.25 
K.W. This is run by a silent chain drive 
off the main propeller shaft and is con- 
trolled by a separate clutch, shown in front 
of the switchboard seen in the photo. The 
generator may be cut in or out at will, by 
means of this clutch. 



ds the Equiv- 
ape. 



A perfectly equipt switchboard is mount- 
ed on the right side immediately above the 
generator, having a marble back in an en- 
closed case with a glass front. It is equipt 
with a master switch for both the bat- 
teries and generators. Also an individual 
switch for each light and gages to show 
amperes and volts, a resistance cut-out and 
small lights to illuminate the board. Fuses 
of proper capacity are installed for each 
switch. To prevent damage to generator or 
batteries an under-load and an over-load 
switch is installed. This acts as a gover- 
nor, the purpose of which is to automatical- 
ly disengage the charging line from the 
generator when the rate of charge reaches 
a dangerous value or when the rate of 
charge is so low that there would be dan- 
ger of the batteries bleeding. 

The portable lights are adapted to be 
used on a tripod. They are mounted on 
the wagon on a swivel connection with a 
one-inch diameter stem projecting, which 
fits into a socket fastened with a nut. 
A similar socket is provided on the tripod 
and when the light is set on the tripod, a 
large hand nut is provided which holds it 
securely. The light mounted on the tripod 
can be readily moved from place to place 
by one man. As he carries the light to 
he fire the reel automatically unwinds. 



A wireless telegraph distance record of 
11,500 miles was establisht by the steamer 
Sonoma, which pickt up messages from Eil- 
vese, Germany, when two days off Austra- 
lia, according to Royden Thomberg and 
Clio Bowers, operators on the Sonoma. 
Ellery Stone, assistant United States radio 
inspector at San Francisco, said it was 
the greatest distance achievement in wire- 
less telegraphy. 



IS 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



MONSTER MOTOR GREATEST 
EVER BUILT. 

We are told that at one time this old 
world of ours was inhabited by gigantic 
monsters. Well, we still have monsters — 
mechanical ones — that are far more pow- 
erful than any of which our ancestors 




The Egyptians Built the Pyramids — but Se 
Builds an Electric Motor Developing the Com 
Horses. This Is the Largest Motor 

knew. Take, for instance, the mastodonic 
Westinghouse reversing motor here shown, 
which was specially designed for driving 
35-inch reversing blooming mills in large 
steel plants. When we realize that it has 
a capacity of 15,000 horsepower, the largest 
electric motor ever built, we need no fur- 
ther proof — we know it is 
monstrous. Some idea of 
its size may be gained when 
it is stated that the man 
standing alongside the mo- 
tor is six feet tall. 



TRAVELING ELECTRIC SIGN FOR 
SHOW-WINDOWS. 

The traveling electric sign here illustra- 
ted is a new moving feature sign for win- 
dow attraction that can be operated where 
heretofore the ordinary signs have been 
used. It displays the same amount of read- 
ing that ordinarily requires 
a 30-ft. length of space into 
a 3 l />-fo. space. The word- 
ing can be changed as often 
as desired. 

Four 10-watt lamps are 
used for illuminating the 
sign, and the motor which 
operates the moving band 
uses only about 20 watts. 
Motor and lamps together 
use about the same 
amount of current as a 
32-c.p. lamp. During 
the daytime, when the 
motor only is working, 
it uses less than one- 
half as much and the 
sign is equally effect- 
ive. 

Any length of film 
from 6 ft. to 30 ft. can 
be used and changed in a few minutes. 

This sign can be operated on either 100 
to 120 volts direct current or 100 to 120 
volts (60 cycle or less) alternating current 
by changing the connections at the termi- 
nal board. 

The sign comes complete, ready for use, 



e How Modern Man 
bined Power of 15,000 
Ever Built. 



The Travelin 
Cabinet, the 



ELECTRIC LIGHTS 
CHEAPER THAN 
KEROSENE. 

How much cheaper are 
gas mantles and electric 
bulbs than candles? The 
Society for Electrical De- 
velopment, anxious to en- 
courage a wider use of elec- 
tricity for lighting, has pre- 
pared figures showing that 
both are much cheaper than 
candles or kerosene, and 
that electric light, while it is 
more expensive than light 
from a gas mantle, is much cheaper than 
light from an open gas flame. 

A recent test of six candles showed 
that for one cent only 2.68 candle-power 
hours were obtained. If electricity for 
lighting costs nine cents for a kilowatt-hour 
a 20-watt lamp can be lighted for 50 hours 
for nine cents. The efficiency of a 20-watt 
incandescent is a candle-power for 1.17 
watts. Thus a 20-watt lamp will provide 
about 17 candle-power. It will burn 50 
hours for nine cents or 850 candle-power 
hours will cost nine cents. One cent will 
buy 94.4 candle-power hours, or 35 times 
as much light as can be obtained from a 
candle for one cent. 

Ordinary kerosene lamps with kerosene 
at 15 cents will give 72 candlepower hours 
for one cent. Figuring electricity at nine 
cents a kilowatt hour as above, we find 72 
candle-power hours for one cent balanced 
against 94 for electricity, or a margin of 
22 candle-power hours in favor of electrici- 
ty. With an open gas flame and gas cost- 
ing 85 cents a thousand cubic feet, one cent 
will buy 51 candle-power hours. For this 
price electricity will provide 94 candle-pow- 
er hours. Thus balancing gas against elec- 
tricity, we find the margin to be 43 in fa- 
vor of electricity. Gas mantles have be- 
come very popular and with best mantles 
one cent will buy 201 candle-power hours. 




g Electric Sign Provides 30 Ft. of Word Space 
Moving Belt Presenting An Ever-changing Sign 
Adapted to Show Windows. 



and can be operated from any convenient 
lamp socket. It can be set anywhere, or 
suspended with cords to hang at the top, 
middle or back of any show window. 

MUNICIPAL TROLLEY OF SEAT- 
TLE LOSES MONEY. 

The municipal street railways of Seattle, 
Wash., continue to lose money, as shown 
by the report of A. L. Valentine, superin- 
tendent of public utilities, in his report for 
October, the net loss being about $2,000 
monthly. Since f.ie city light dept.rtment 
took over the street railway substations the 
power cost is being checked against the 
value of the substations, so that in October 
the street railways received $1,069 worth of 
power without cash outlay. 

SAYS U.S. SHIPS HAVE GREATEST 
RADIO RANGE. 

After he had inspected radio apparatus 
on a number of vessels recently, Secretary 
Redfield of the Department of Commerce 
said that American vessels have a wider 
range in sending and receiving messages 
than ships of other countries. He also as- 
serted that, from a comparison which he 
made of apparatus cn an. American and a 
British steamer, the wireless regulations 
past by Congress give greater power to ra- 
dio inspectors than do British regulations. 



NEW VACUUM BULB RECTIFIER 
FOR BATTERY CHARGING. 

The latest novelty in small rectifiers for 
charging storage batteries rated at 2 to 6 
amperes charging rate and from 7.5 to 75 
volts is here illustrated. It operates on a 
new principle for this class of apparatus. 
The discovery that made it possible is the 
perfection of the small bulb similar to that 
of an incandescent lamp, in which recti- 
fication of the current takes place. This 
bulb is filled with an inert gas and contains 
a tungsten filament and a grafite anode. It 
screws into a lamp socket in the outfit. 

A black-japanned casing with perforated 
top furnishes the mounting and incloses all 
live parts. This casing carries the bulb, a 
fuse to protect against reversal and other 
overload and the compensator which re- 
duces the alternating current without waste- 
ful resistance and excites the tungsten fila- 
ment. For charging, the rectifiers need 
only be connected to a convenient lamp 
socket and the pair of leads attached to the 
proper posts on the battery. 

The smallest unit is of 2 amp. maximum 
capacity. From a 115 volt, 60 cycle alter- 
nating current circuit it will charge three 
lead battery cells at 2 amp., six cells at 
about 1 amp., and eight cells at 0.75 amp. 
Between these figures the charging rate is 
proportionate. At 10 cents the kilowatt 
hour for current, the cost is about 1 cent 
the hour, including tube renewal costs. The 
weight is about 15 lbs. Medium size recti- 
fiers have a capacity of 6 amp., 7.5 to 15 
volts, and are designed pri- 
marily for charging three or 
six-cell automobile starting 
or lighting batteries in home 
garages. This type is de- 
signed for 115 volts, 60-cy- 
cle current, but may be used 
on 105- to 125-volt circuits. 
The weight is about 15 lbs. 
The largest type is designed 
for use in public garages 
and service stations, and 
has a capacity of 6 amp., 
7.5 to 75 volts. It will 
charge from one to ten 
three-cell storage batteries 
from a 11 5- volt, 60-cycle, 
alternating-current circuit. 
A compensator with fifteen 
taps is part of the device 
and a dial switch for in- 
stantly adjusting voltage ac- 
cording to the number of batteries to be 
charged. Amperage can be regulated be- 
tween limits of 1 and 6 amp. A single 



in a 3/2 Ft. 
— Particularly 




New Vacuum Bulb Rectifier with 
Control Handle and Ammeter, De- 
signed for Charging Storage Batteries. 



three-cell battery may be charged by itself 
or any number up to and including thirty 
cells. The controlling devices, including 
ammeter, switch and regulating handle, are 
located on the front of the case as seen. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



19 



CIVIC FORUM MEDAL FOR 
DR. BELL. 

Dr. Alexander Graham Bell, inventor 
of the telephone, before a gathering which 
filled Carnegie Hall, received the Civic 
Forum Medal of Honor for Distinguished 
Public Service on March twenty-first. 
This medal was presented in 1914 to Maj- 
or-general George VV. Goethals and in 1915 
to Thomas Alva Edison. After many elo- 
quent speeches in his praise, Dr. Bell re- 
sponded modestly, endeavoring to share the 
tributes to him with those who have been 
associated with him in developing the tele- 
phone. < 

"I may perhaps claim the credit of blaz- 
ing the trail," he said, "but I am embar- 
rassed at all the honor which has been 
done me, because so much of it should go 
to the many men who have since improved 
upon and extended its use — to such men 
as Mr. Carty and his associates. Why, I 
am not even able to understand some of 
the mechanism which they have introduced 
into the use of the telephone. When they 
telephoned from Arlington and were heard 
at Eiffel Tower in Paris, I could not see 
how it was done, nor could I understand 
how an operator in Hawaii was able to 
pick up the message." 

Dr. Bell told how, shortly after he got 
the idea of the telephone in 1874, he had 
called on Professor Henry at the Smith- 
sonian Institution, who was then recog- 
nized as the greatest authority on electric- 
ity in America. Professor Henry listened 
kindly to his plan, and told him that he 
thought he had the germ of a great inven- 
tion. 

"I told him that the trouble was that 
I did not have enough knowledge of elec- 
tricity," said Dr. Bell. "He said, 'Get it.' 
Now the fact is that, had I known much 
about electricity, I would never have in- 
vented the telephone. I 
would have thrown up the 
idea as wildly improbable. 
My study had been that 
of sound." 



HEINRICH HERTZ. 
Born Feb. 22, 1857. Died Jan. 1, 1899. 
Inventor of Wireless. 

HEINRICH HERTZ was born on Feb- 
ruary 22, 1857, in Hamburg, Germany. 
He received his early training in the 
engineering schools but at the age of twen- 
ty-one he decided upon an academic career 




Heinrich Rudolph Hertz — Father of the Wire- 
less Telegraph. Upon His Scientific Re- 
searches and Practical Demonstration of 
Maxwell's Electromagnetic Theory, Marconi 
and Others Have Built Up the Commercial 
System We Know To-Day. 

and entered the University of Berlin as a 
pupil of Von Helmholtz and Kirchoff. 

Of the many gifted students of physics 
who have come forth from the celebrated 



A NEW INSULATING 
MATERIAL. 

"Galalith" is a bone-like 
substance similar in many 
respects to celluloid. It is 
manufactured from casein 
and formaldehyde. A solu- 
tion of casein is obtained 
by treating skimmed milk 
with caustic alkali, after 
which the solution is clari- 
fied and the casein then 
precipitated by means of 
acids and filtered. The 
water is then extracted 
under pressure and the 
product slowly dried over 
a period extending several 
weeks. The product ob- 
tained is casein plate, 
which is treated by thoro 
saturation with formalde- 
hyde and dried again. 
Galalith is said to be an 
excellent insulating mate- 
rial somewhat transparent, 
altho never completely so, 
and of a yellowish-white 
horn-like color. It is 
workable either in the hot 
or cold state, the cold gala- 
lith being softened by 
treatment in hot water. It 
is odorless, and much less 
inflammable than celluloid. 
It cannot be made into very thin sheets. 

Senator Sheppard recently introduced an 
amendment to the naval appropriation bill 
calling for $50,000 to be expended in the 
erection of a radio station at Galveston. 



TO ALL RADIO AMATEURS. 
rrfHE Department of Commerce of Washington, by its Secretary, the t 
/ Hon. JVm. C. Red field, has kindly sent us the following information j 
of particular interest to all amateurs in the United States at the pres- J 
ent time. I 

Secretary Redficld has issued orders that for the present no ne"w licenses 
to radio amateurs will be issued and the renewal of outstanding amateur 
licenses will be granted only by the Department upon special favorable re- 
ports by the radio inspectors. (This refers to sending outfits only.) 

The Department also informs our readers, reminding them of the fact 
that the operation of transmitting radio instruments without licenses is pro- 
hibited under severe penalties, which, under the conditions of the time, 
would be exacted in the case of those who showed no- regard for the re- 
quirements of the law. 

Up to the time that we go to press, the Department has not formulated 
final plans as to what steps will be taken in regard to radio amateurs as 
a whole, and -whether they will be allowed to continue to operate the same 
as before. It is our personal impression, however, that no drastic steps 
are likely to be taken by the Government as long as the amateurs cooper- 
ate with the Department. . 

In view of this we most urgently and earnestly request all amateurs at 
the present time to refrain from using their transmitting stations except for 
regular work. In other words, all unnecessary gossip and fooling should be 
rigidly suspended for the present, particularly the "Q.R.M." nuisance which 
at best, only serves to irritate our officials, and makes their work harder. 
If amateurs do not voluntarily stop such annoyance the Government will 
certainly prohibit the use of all privately owned radio outfits. 

These are no times to use the ether for a lot of nonsense; we all wish 
to help our country as much as we possibly can until normal conditions are 
restored again. 

Always remember, that our Government has granted the radio amateurs 
more powers than any other country in the world, and in times of stress, 
it is up to the amateurs to show of what stuff they arc made by cooper- 
ating with our officials to the fullest extent of their powers. 

THE EDITOR. 



Berlin laboratory, there are probably none 
who have become so world-famous as Hein- 
rich Hertz. His qualities as an investigator 
were speedily recognized by Von Helm- 
holtz, who urged him while still a student, 
to undertake the solution of the prize prob- 



lem proposed by the Berlin Academy of 
Sciences in 1879. 

From 1880 to 1883 Dr. Hertz was an as- 
sistant in Von Helmholtz's laboratory; he 
then lectured for two years as instructor at 
Kiel. From 1885 to 1889, he was professor 
of physics in the Polytechnische of Karls- 
ruhe. In the latter year Clausius, a pro- 
fessor of this institution, died, and Hertz 
was selected as his successor in the Univer- 
sity of Bonn, where he spent the few re- 
maining years of his life. 

Hertz's career as a scientific investigator 
covered a period of scarcely more than ten 
years, during which time he publisht thirty- 
six papers. Of these, a series of thirteen 
which appeared in Wiedemann's Annalen, 
were upon the subject with which his name 
will forever be connected, the laws of the 
propagation of electro-magnetic induction 
thru space. Of this great work, which af- 
forded a complete experimental verification 
of the Maxwellian theories concerning elec- 
tro-magnetism and the relation of electric- 
ity to light, there is no need to speak of its 
great importance to the scientific world. 

The importance of Hertz's contributions 
to this great subject received instant recog- 
nition. It would indeed be difficult to find 
any other instance in which researches bear- 
ing upon a most subtle and difficult ques- 
tion, and absolutely devoid of basic elements 
of a utilitarian or even of a popular char- 
acter, having secured to their author such 
sudden fame. In addition to the recogni- 
tion of those wno were able to appreciate 
his work, Hertz received the acclamations 
of the entire world of thought. Fortun- 
ately, he possest a nature of such complete 
simple-mindedness that his sudden rise into 
a position akin to notoriety had no effect 
upon him. The unassuming bearing which 
had always characterized him remained 
with him to the end. 

„,„ „ „■„-„„„..« In delightful harmony 

I with the genuine and sim- 
1 pie nature of the man 
were his surroundings in 
the quiet university town 
of Bonn. His laboratory 
was situated in the apart- 
ments formerly occupied 
as a dwelling by Clausius 
in a wing of the old pal- 
ace. Since electricity has 
become utilitarian, we find 
it associated everywhere 
with moving machinery 
and with the rush and 
bustle of modern indus- 
trial life, but in Hertz's 
laboratory, there was noth- 
ing to suggest the science 
of electro-technics. The 
place seemed to breathe 
that spirit of academic re- 
pose which to the inmates 
of the present day must 
have seemed to have van- 
ished altogether from the 
world. What might such 
a man, in such an en- 
vironment, have not been 
able to achieve, had he 
lived ? 

The promulgation of 
the theories of Dr. Hein- 
rich Hertz in connection 
with Wireless waves, 
stimulated universal inter- 
est all over the world, 
which led to their use in 
the propagation of intelli- 
gence thru free space. 
In 1892, Hertz's re- 
searches upon the electric waves were gath- 
ered together in a volume under the title 
"Untersuchungen ueber die Ausbreitung der 
Elektrischen Kraft." Almost on the day 
of his death, another excellent translation 
of Hertz's researches appeared. 



20 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



L 



IEUTENANT Commander Par- 
ker, U.S. submarine 'F-609.' Our 
torpedoes useless. Proceed at 
once and see if you can do any- 
thing. Enemy's defense perfect. 
Admiral Gregg, U.S.N., 
Commanding Flotilla." 
T glanced up from reading this message, 
scrawled on a scrap of paper, to ask Park- 
er what it meant, but he was not there. I 
heard him in the forward compartment 
issuing orders in his rapid-fire manner. 

It puzzled me, this brief dispatch which 
Parker had translated from the muddle of 
code words that had come in over my 
wireless. Could it be that the great fleet 
of submarines now in mid-Atlantic, sup- 
posed to be torpedoing the enemy's fleet 



"Eddy Currents" 

By C. M. ADAMS 

we went out, thirty-two knots an hour, 
headed for the open sea. 

As we went I picked up a message with 
my wireless which seemed to be related to 
the information in the code message Billy 
had received. It was a* press dispatch and 
read : 

"There is a report that the defensive 
submarine flotilla which was to meet the 
imperial fleet in mid-ocean, is helpless be- 
cause of the excellent defense of the im- 
perial fleet against torpedo attack. The re- 
port says that the submarines have dis- 
charged every torpedo aboard and have not 
damaged a single enemy ship. 

"The imperial fleet was reported by aero- 
scouts to be of sixteen battleships, to- 
gether with eight destroyers and followed 



by our navy with its present equipment. 
How could we save our country from the 
invader? How could we stay off the de- 
feat which seemed iminent when that won- 
derfully trained army got into action 
against our meager forces? 

I voiced these sentiments when, about 
nine o'clock I found Billy standing beside 
the conning tower on the open deck, look- 
ing forward over the double wave that 
marked our bows. 

I felt free to ask Billy Parker much, for 
we had been old classmates at the Tech. 
school before he went into his electrical 
engineering work and I drifted off into 
mine, not seeing each other until I dropt 
into this craft as its wireless operator 
when the call came to me from the navy. 




Once Again He Called to Start the Alternator. The Hum of the Machine Sounded and as Before the Switch Was Deprest. 

and Found That It Was Held Down Six and a Half Minutes. 



I Timed It Now 



as it tried to approach our shores, had failed 
in its mission? Were the new powerful 
torpedoes, loaded with hundreds of pounds 
of high explosive, and the great mechani- 
cal fish which launched them, useless as 
far as defense was concerned? I wanted 
to ask Billy Parker these and many other 
questions but he was busy. 

An hour after this message had .-ome 
buzzing in we cast off our moorings and 
were slipping out thru the harbor dotted 
with hurrying navy craft. We did not at- 
tract any unusual attention, for submarines 
were quite common sights in these times. 
Soon we past Sandy Hook, thru the line 
of patrolling cruisers, then out into the 
open sea. Our turbines were purring 
smoothly and our driving motors were 
spinning like great smooth-running tops as 



by twenty transports carrying the invading 
army. There are also several enemy aero- 
planes which accompany the enemy fleet." 

Evidently something was wrong with the 
defense planned by the navy officials. The 
fifty great under-sea craft were not doing 
their duty, which had been to sink as many 
of the invader's ships as possible. I puz- 
zled over this as I sat about waiting for my 
call and wondered what we would do now 
that our chief defense had gone. 

What would happen when the army in 
those twenty transports landed on our 
shore, unprotected save by the scanty coast 
defense guns, made scantier by the appro- 
priation for submarines, and met our vol- 
unteer army in a pitched battle? This truly 
was a surprise, an overwhelming, unex- 
pected contingency which could not be met 



Wireless operator was all I was good for, 
owing to my lame leg. 

"What will happen now that our sub- 
marines are helpless?" I asked. 

"It's up to the coast defense and the fleet 
if we can't stop them," he said, looking 
away ahead where the sea rolled under the 
faint stars. 

Billy confided in me. His showing me 
the translated code message proved that. 
But this was a new turn. 

"If we can't stop them?" I repeated 
blankly. 

It had not occurred to me that we were 
going to try to stop them at all. I did not 
know why we were going, but it seemed 
obviously impossible for us to do anything 
in that direction when the rest of the sub- 
marines had failed. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



21 



"Yes, if we can't stop them," he repeated 
after me. 

"Why, we won't be any better than the 
rest of them. That torpedo defense is 
too good," I argued. 

"Who> said anything about torpedoes at 
all?" he demanded, wheeling and staring 
at me aggressively. , 

"Well, we're only a sub- 
marine," I retorted. — 

"Does that mean that 
we necessarily have to use 
torpedoes?" he countered. 



netic coil mounted on a revolving and in- 
clined carrier. This coil is shaped and 
wound so that its lines of force are kept 
within a very small area, in this case about 
one and three tenths square feet. Conse- 
quently when a metal object passes thru 
this relatively intense field, the induced 
current in the metal object will be sufficient 



don't wei 



I 



"Why, 
asked. 

"We haven't a thing 
that resembles a torpedo 
on this boat except the 
shells for that three-inch 
gun under the deck, and 
they will be about as ef- 
fective against a battleship 
as birdshot against an 
elephant." 

I stared at him a long m^^^^^^^^ 
time then. He was seri- — 
ous as I could see, even 
in the starlight, but he was not lucid. 

"Well, how are we going to get them 
then?" I asked, thinking that this natural 
question was expected of me. 

"I'll show you," he answered, and 
stept down the ladder leading below. 

I made to follow. 

"No, stay there," he commanded. 

I did, leaning against the steel conning 
i tower. A moment later I heard the sound 
of mechanism close to my head and glanc- 
ing up I saw something appear above the 
conning tower. I climbed upon the low 
rail and looked up to see what it was. 

The steel plates had opened in the cen- 
ter and from the opening had emerged 
a hemispherical object, made of what ap- 
peared to be very heavy glass and measur- 
ing about three feet in diameter. Inside 
it was what looked to be a small mechani- 
cal device which seemed to run on a small 
circular track. 

I was busy examining the device when 
I heard Parker beside me. 

"That," he said, "Is the Feeler." 

"The feeler?" I repeated, this was new 
to me. 

"Yes, the feeler, a device that will locate 
any ship within ten thousand yards, with- 
out any part of our boat being seen." 

I looked at the device again with in- 
creased interest. I could not see anything 
distinctive about it. 

"Don't you see how it works?" Parker 
asked. 

"No, I can't say that I do," I admitted. 

"Come on down in the control room and 
I'll show you." 

He led the way down the ladder and 
we went into the little box of a room under 
the conning tower where one is afraid to 
lean against the wall for fear of starting 
or stopping something necessary to the 
life of the boat. 

He picked out a glass case from among the 
litter of instruments on the walls and 
pointed it out to me. It was not a very 
big case. In it were three dials, an elec- 
tric lamp and below it were three small 
control wheels. It looked very much like 
the other dials and wheels so thick about 
me, and was distinguished only by the 
word "Feeler" on the case. 

"This device," he said, "works on the 
principle of electro-magnetic induction. 
You know what that is, the setting up of 
a current in something that cuts the field 
of force caused by a magnet. Well, up 
there in that glass case which will stand 
any pressure the boat hull will, is a mag- 



"^^"E have publisht a great many stories in the past, but we do not 
hesitate to state that "Eddy Currents" is one of the very cleverest 
we have ever printed. Not only is it a rattling good story, but the scheme 
is so plausible that we venture to prophesy that it will be actually tried 
in the not too distant future. And then, the submarine will earn its 
adjective "deadly" in the fullest sense of the term. 



to make a difference in the load on the 
coil. You see that don't you?" 

I did. That was perfectly plain sailing, 
electrically. 

"Well then, when this load comes on, 
the lamp lights up as a signal, and this 
dial here which is really a calibrated gal- 
vanometer, shows how far away the ob- 
ject is." 

He pointed to one of the three dials 
which 1 had noticed was calibrated in 
yards. 



IN THE JUNE "E. E." 

An interview with Thomas Alva 
Edison, including some new photo- 
graphs of the famous inventor. 

Electricity and Life by Dr. Fred- 
erick Finch Strong. Part III of 
this interesting and valuable series. 

Woman's place in the Wireless 
game — A page of female radio 
operators who have made good. 

The How and Why of Radio Ap- 
paratus. Part IV. Spark Gaps. 

The Calculation and Measure- 
ment of Inductance. Part III of 
this valuable series by H. Winficld 
Secor and Samuel Cohen. 

Another gripping electrical tale — 
"In the Way" by C. M. Adams. 
Don't miss it! 

Feature Article — "Electricity's Aid 
to the Fair Sex" — of interest to 
everyone. 

Building a High Frequency Alter- 
nator for use in Radio by S. Cohen. 

Experimental Physics. Fifth 
Paper by John J. Furia, A.B., M.A. 

An Electric Player for Tuba- 
phones. 

A home-made electric searchlight 
for the amateur by Frank M. Jack- 
■ son. 



"What are the other dials for?" I asked. 

"They are to give the angle of the coil, 
both in the horizontal and vertical planes. 
You see both are calibrated that way. 
These wheels here turn the coils about 
and raise and lower them, and this third 
wheel operates the mechanism which raises 



the coils clear of the conning tower." 

I saw then the whole perfect simplicity 
and accuracy of the device. I marveled at 
it. 

"Then you can run under water with- 
out even a periscope exposed and locate 
the exact position of the enemy," I said. 

"Exactly, you understand it perfectly,' 
he replied. 

— — — — — — - "Then you can aim your 

~~"^™"™""~" — torpedo with accuracy," I 
went on. 

"Torpedo !" he snorted 
with an exasperated 
frown. "Didn't I tell you 
that we didn't have one of 
those antiquated devices 
aboard this craft?" 

"But," I went on, "you 
must have something to 
sink the enemy after lo- 
cating him." 

"We have," he said, his 
face brightening hope- 

_ — full y- 

"Well, what is it?" I 
asked, puzzled. 

"Look here, Dick Hartman," he said in 
mock seriousness, "do you mean to tell 
me that after seeing this feeler work, you 
can't understand how we could sink a ship? 
You, a graduate of the best technical school 
in the country and a practical electrical 
engineer, can't understand that?" 

I contest that I did not. 

"Then you're either asleep or haven't the 
least trace of imagination," he said, turn- 
ing away in disgust. 

"Well, how do you do it anyhow?" I 
asked. 

"I'm not going to tell you. I'll let you 
find out for yourself first," he retorted 
with a show of his old boyish perversity, 
and walked into his room and left me 
wondering in front of the feeler dial. 

But I could not follow his line of reas- 
oning to its end. I thought of it as I tried 
to sleep that night, while the motors 
thrust us forward and our long hull swayed 
gently as we topt the crests and fell into 
the hollows. I puzzled over it as I sat 
at my instruments and waited for my call, 
or anything else my receivers could pick 
from the ethereal vibrations about us. But 
I could make nothing of it. I could see 
no way, no means by which wc could sink 
an enemy ship with this curious little feeler 
device which with all, was exactingly ac- 
curate. 

All that night we ran and all the next 
day. I did not ask Billy any more about 
our boat. Pride perhaps kept me from 
doing this, and impatience at my own lack 
of perspicuity and imagination. And then 
too I was busy with my own work and 
other things that came up, which had to 
be done in the crowded under-sea craft. 

I prowled about it in what spare time I 
had, trying to see what I could between 
tricks at my table. I found that it was 
quite the usual large-sized submarine, of 
which the navy had an even hundred not 
counting ours. It was driven by electric 
motors supplied by turbine driven genera- 
tors forward. It was provided with the 
usual gas absorption system which made 
it possible to run under water with our 
steam power, without discharging any ex- 
haust gases; this, the 'first important in- 
vention of the Naval Consulting Board. But 
I found the forward torpedo room locked 
and none on board had gone into it since 
they had been on board, none save the 
chief engineer, Dickenson, a man from 
Parker's own electrical company, which 
had built this curious boat and sent it out 
(Continued on page 66) 



LIBRARY 



11 <? patent nrri/c 



22 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



118 VOLTS CAN KILL. 

The Ontario Electrical Inspection De- 
partment of the Hydro Commission are out 
hot foot after delinquents who try to work 
in jobs without permits and convictions are 
being rendered every week, says a writer in 
the Electrical Safety Magazine. 




Never Touch Electric Light Fittings or Wir- 
ing While Standing In a Bath-Tub or On 
Damp Floor, as the Consequences May Prove 
Fatal. 

One person is to come up before the 
board for refusing inspector admission to 
premises and others for not returning to 
remedy defects on jobs before expira- 
tion of inspectors' notices. 

In the City of Toronto, in the month 
of October, a young man, nineteen years 
of age, was in the bath-tub and, so far 
as his parents knew, he was enjoying 
the harmless and healthful pastime im- 
mensely, judging by the sounds of 
splashing and rubbing emanating from 
the keyhole. 

The happy sounds were suddenly in- 
terrupted by a deathly shriek, and his 
parents upon breaking into the room, 
found him doubled up with the coils of 
a long portable lamp cord wound round 
him and the portable lamp in the bath. 
The lamp was an ordinary brass desk 
lamp provided with the silk cord. 

The cord was worn, showing bare 
copper spots. What he was doing with 
a lamp in the bath no one knows. 

The bathroom was provided with a 
brass bracket well up above the bath with 
a portable socket. 

Test revealed that 118 volts, 25 cycle cur- 
rent was used, one side grounded, the fix- 
ture itself clear of ground and well insu- 
lated from both the grounded and un- 
grounded sides of the circuits. 

The investigations show that he was 
killed by coming in contact with brazed 
cord carrying 118 volts, 25 cycle current. 

This proves two things: First, that 118 
volts can kill, and secondly, that indif- 
ference to bare spots on cord is dangerous. 

One quarter of a dollar spent on renew- 
ing this cord would have saved a young 
life, a doctor's bill, an undertaker's bill, 
and the parents' grief. Is it not worth 
while? Safety First! should be the slo- 
gan of every user of electric service, 
whether for half a dozen lamps or for a 
large factory. Again — when you stand on 
a damp or wet floor or in a bath-tub, don't 
touch an electric switch or fixture! 



their entire life a pair of these shoes, the 
manufacturer states, will provide the wear- 
er protection against circuits at pressures 
up to 20,000 volts and will not cause the 
discomforts of many of the rubber soles. 

The shoes are molded by a process simi- 
lar to that used in making automobile tires. 
The shoes contain no cement and have no 
seams, but are vulcanized into a solid piece 
under high pressure on aluminum molds. 
No hand work is employed in the process. 
This method of manufacture makes it im- 
possible for the completed shoe to peel or 
come apart and prevents injury from oil, 
gasoline or grease. 

In order that the shoes may, in the inter- 
est of safety, be distinctive, they are all 
made exactly alike with brown heels, white 
soles, brown vamps and black tops. The 
white soles are made of a rubber composi- 
tion like that employed in certain types of 
coal miners' shoes, which have been found 
to give eighteen months of constant wear. 
When this white sole wears thru, a layer 
of red rubber, which will itself with- 
stand a pressure of 20,000 volts, is exposed 
The appearance of the red rubber is a sig- 
nal or reminder to the wearer that, altho 
his shoes still will withstand 20,000 volts, 
a new half sole should be immediately ce- 
mented or vulcanized in place. 

The brown rubber also extends under the 
white sole. It is this piece of material 
which is capable of withstanding high po- 
tentials. One of these shoes, when tested 



S(Vtf!er/Vogf//f/7or?re<?je 



insu/afed so/e of red 
rubber tested eo.ooo v\ 



proof <?/?d /toffee fed 6y 
tiejt /tor cofd 

(//>//># embedded m 
itt/tier to prevent 
jbjor/)t/o/? <f/77o/3fi/re 



Outer s//r&ceqffouob 
retfruMev- fejfedto ^ 
c~o 000 voffs J? Z//7Cfe3 
o/irsterj/fer }<ooeo 
///p/jAed 



Outer sofe wb/tejvt . 
rei/sfwg vwatff/zeq c//s 
trejd rubber wfar/i ir/fb- 
sbnds 3QOOO voftj 




L tfo/7-moafi/re I 

Jbsorbw? casAroo 

ffeet of tougti) 
ifear-res/stir?g rubier 



Remarkable New Shoe for Lineman Which Is 
Capable of Withstanding 20,000 Volts. Note That 
No Nails Are Used. 

in the laboratories of the Edison Electric 
Illuminating Company of Boston, under the 
direction of the accident prevention com- 
mittee of the National Electric Light Asso- 
ciation, showed the following characteris- 
tics : 

"Side of shoe, dry, punctured at 31,500 
volts, and again at 34,000 volts ; sole of 
shoe between electrodes in oil punctured at 
55,000 volts; 20,000 volts applied from salt 
water to salt water for one minute and 
30,000 volts applied from salt water to salt 
water for forty-five seconds did not punc- 
ture the rubber." 



point, were about seven feet above the lo- 
comotive, and current is sent thru them 
at a pressure of 11,000 volts, 25 cycles. 

Directly over the engine, which was giv- 
ing off a medium black smoke, the air 
seemed to flicker at the rate an electric 
light would if connected to a 25 cycle cir- 
cuit. This *vas only noticeable when the 
quality of the smoke's carbon element was 
just right. That this flickering was not due 
to heat waves I proved by the fact that 
objects when looked at thru heat waves 
seem to bend or wave from side to side and 
move upward, while objects seen thru this 
vibrating air did neither, and when the 
quantity of carbon decreased as the wind 
blew, the flickering effect disappeared. 

The cause of this phenomena I attribute 
to the attraction and repulsion of the car- 
bon particles in the smoke and as the cur- 
rent reversed they were drawn upward and 
downward for a very short distance, while 
being dissipated into the atmosphere. The 
effect was not noticed a few inches above 
the wire. The weather on January tenth 
was slightly hazy, with no sun at 3.30 p.m., 
when this effect was noticed. In bright 
sunlight it could not have been seen. If 
my explanation is in error I shall be pleased 
to hear the views of some of your technic- 
ally inclined readers. 

MAKE YOUR PHOTO PRINTS BY 
ELECTRICITY. 

The electric photograph printer illustra- 
ted has been brought out for both pro- 
fessional and amateur use. A feature 
of the device is an automatic switch 
which is operated only when full pres- 
sure is placed on the pad. The pressure 
pad is placed in position by a hand lever 
which controls the automatic switch, the 
'light being turned on only when full 
pressure is exerted on the pad. The 
light is -turned off before pressure on the 
pad is released, thus avoiding any blur- 
ring in the prints and assuring absolute, 
contact. A locking device is provi- 
ded which relieves the operator of 
the necessity of maintaining pressure on 
the lever during the exposing period. 
With a slight grip on the release catch, 
the lever can be freed. A locking de- 
vice is also provided, permitting the 
white light to be turned on and the pres- 
sure pad elevated to permit accurate ad- 
justment of masks or vignettes. In the 
light box of the smaller printer are one 
ruby and four clear incandescent lamps, 
and in the larger one there are one ruby 
and six clear incandescent lamps. The 
printers are designed to take 100-watt gas- 
filled lamps. 



ELECTRICITY LIGHTS NEW PIPE. 

An electrically ignited pipe which lights 
the tobacco at the bottom of the bowl in- 
stead of at the top, thus avoiding the col- 
lection of moisture in the stem, is the new- 
est in smokers' inventions. 



A LINEMAN'S SHOE THAT WITH- 
STANDS 20,000 VOLTS. 

A leading American maker of lineman's 
protective devices, which for several years 
has been marketing protective shields to 
cover wires and cross-arms where men are 
working, has now developed an insulat- 
ing shoe for electrical workers. Thruout 



PECULIAR ELECTRICAL 
PHENOMENA. 
By Walter J. Howell. 

While standing about one hundred feet 
away from the tracks of the New York, 
New Haven and Hartford Railway January 
10, 1917, a large steam engine pulling a 
heavy freight train past at the rate of five 
to eight miles per hour. The railroad is 
electrified by overhead wires, which, at this 




Electrically Illuminated Photograph Printer 
Equipt with Automatic Switch Actuated By 
Printing Frame. 

The printer is being made in two sizes — 
8 in., by 10 in., and 11 in., by 14 in. 



May, 1917 




THE ELECTRICAL EXPERIMENTER 

™° RADIO LEAGUE 



^AMERICA 



H. Gcrnsback, Manager 



H ON OR ART MEMBERS 
CAPT. WHG. BUILARD. U. S.N. NIKOLA TESL A 
PROF. REGINALD FESSENDEN. DR. LEE DE FOREST. 

W. H. Kirwan, Master of Radio Relays 




The Washington's Birthday Relay Prize Winners 



WELL, boys, you did it ; the 
first official Trans-continental 
M.S.G. (message) No. 1 from 
the Mayor of New York to 
the Mayor of Los Angeles, 
went thru with the customary speed and 




Mr. Edward B. Duval!, Who with Mr. A. P. 
Smith, Operating Station "3AK," Baltimore, 
Md., Won "First Prize" in the Washington's 
Birthday Relay. 

reliability of all the Relay messages we 
have worked on. The special stations 
sent the westbound message from New 
'York on this night from 2 ZK 
at New Rochelle, using 8 YI, 9 
XM and 9 ZF to 6 EA, which 
last station is in Los Angeles, 
Cal. Considering the time, one 
and one-half hours, and the 
great "QRM" (interference) 
and the repeating of message 
on account of misspelt words, 
it was truly wonderful. 

The westbound message used 
special stations only and was 
as follows : 

To the Mayors of Los Ange- 
les, Cal., and Seattle, Wash.: 
On behalf of New York City, 
I send cordial greetings to 
Los Angeles and Seattle, and 
best wishes for the success of 
the Radio System. 
(Signed) 

John Purroy Mitchel, 
Mayor of New York. 
Thousands of amateurs cop- 
ied this message with varying 
degrees of exactness thruout the country, 
as four heaping bushels of letters have 
shown. This was the first relay attempted 



By W. H. KIRWAN, (9XE) 
Master Radio Relays, Radio League of America 

by the writer, the necessary notices of 
which were publisht in this magazine. 
Some of you did not hear about the Re- 
lay because you are not regular subscrib- 
ers. Let this be a lesson — Get your name 
down so that you will receive your maga- 
zine promptly and regularly. 

Now, here comes the sad part. You 
will see "by the papers," that on this night 
we had good radio weather as far as the 
Rockies, but the writer had studied the 
weather man and looked for trouble south- 
west and west, and we had it ! A healthy 
young cyclone was dancing merrily over 
Texas, Arizona, New Mexico and Califor- 
nia, and the tail end of a regular old-time 
"QRM" storm was making life miserable 
for the boys in the war west, but with it 
all, 6 EA got the message direct from 9 
ZF. 6 DM, who volunteered to help 6 
EA, put on full power and promptly blew 
the fields of his gap motor, leaving 6 EA 
to do the honors and, by golly, he did. 

Seefred Bros., delivered this message to 
the Mayor of Los Angeles, and promptly 
received his reply, but QRM and QRN 
were so bad by this time that it was a 
physical impossibility to get it thru to 9 
ZF. 6 EA stuck to his post, however, and 
got the message thru the next night, too 
late for 9 ZF to find anyone out of bed. 
9 XE arranged for all eastbound amateurs 
to be on the job, and the message came 
thru fine, being delivered to the Mayor of 
New York by Mr. Geo. C. Cannon, 2 ZK, 
the next morning early. 

Lots of you kept me company by stay- 
ing up all night waiting for the return 
message and now you know why it could 
not get back on schedule. The return mes- 
sage was as follows : 
To the Mayor of New York City: 

On behalf of the City of Los Angeles, 



sage. (Signed) Fred I. Woodman, 
Mayor of Los Angeles. 

By counting up the total time consumed 
on each message, we -call the race between 
Specials and Amateurs a tie, with the 





Radio Station "3 AK," Baltimore, Md., at Which the Wash 
Birthday M.S.G. Was Successfully Received in Record 



I return your greetings and wish you 
continued prosperity. Congratulations to 
Amateur Radio on the successful mes- 



Mr. A. P. Smith, Joint Operator of Radio 
Station "3AK," and to Whom Full Share of 
the Credit for the Receipt of the Relay 
M.S.G. Is Due. 

handicap of the low wave length of the 
amateurs, giving them a slight preference 
for a decision in their favor, but my form- 
er contention still holds — that 
the amateurs are not yet pre- 
pared to handle these trans- 
continental messages with as 
great a degree of certainty as 
the Specials, unless they can get 
together and have emergency 
stations in the long jumps. 

I am not posing as an expert, 
but candidly believe that fifty 
miles, worked absolutely sure, 
with a great number of relay 
stations, is more reliable than a 
few with long jumps, working 
only when the conditions per- 
mit. This is what we propose 
to do now by organizing the 
"Q.R.M. League." In it, there 
will be a chance for all of you 
to help and not just a few thru- 
out the country who want to 
work every night, and who 
want you to shut up. You 
know, boys, this good old 
U.S.A. is a pretty big place and 
these Relays are run for your benefit, but 
there are some few in this country who 
(Continued on page 61) 



ington's 
Time. 



24 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



Electricity and Life 



IN the March number of The Elec- 
trical Experimenter the author point- 
ed out that high-frequency currents, 
when properly tuned, acted as "Vital 
Boosters," increasing all the functions 
of the body and helping it to resist and 



The Construction of High-Frequency Apparatus for Medical and Lecture Use 
By FREDERICK FINCH STRONG, M. D. 
Lecturer on Electro-therapeutics, Tufts Medical School, Boston 

(Second Article) 

The author has interviewed a number 
of the more prominent authorities on med- 
ical electricity and they agree as to the 
vitalizing effects resulting from daily high 
frequency treatment. 

Anyone who possesses a V\ or l /z K.W. 
wireless transformer, operating on 110 volt, 
60 cycle A.C., can easily construct an effi- 
cient high-frequency outfit for medical or 
lecture use. The complete equipment in- 
cludes a .01 microfarad glass plate con- 
denser, Tesla coil, inductance, spark gap 
and electrodes. 

The Tesla coil is made as follows: (Fig. 
3) On a paper mailing tube 2j4" diam. and 
14" long wind 480 turns of No. 34 D.C.C. 
copper magnet wire. Set up the tube in 
the lathe, apply a coat of orange shellac, 
spin on the wire, apply a second coat of 
shellac and allow to dry thoroly. The 
winding occupies twelve inches, leaving a 
margin of one inch on each end of the tube. 
Leads of light auto (ignition) cable are 
^soldered to the ends of the winding. A 
'.strip of waxed, corrugated paper M, 5" 
wide is wrapt around the center of the sec- 
ondary tube and on this is wound the pri- 
mary, consisting of four turns of heavy 
high tension auto cable, and thoroly se- 
cured by tape; at least a foot of cable 
should project from each end of the wind- 
ing to form the primary leads. Place the 
coil in a wax tight box made without nails 
and embed it in a mixture of four parts 
rosin and one part beeswax. It is safer to 
boil the coil for an hour in the insulating 
mixture before placing it in the box. Coils 
made in this way by the writer are still 
giving good service after fifteen years of 
use. 

The greatest source of trouble in a medi- 
cal high-frequency outfit is the spark gap; 
the one described below is the outcome 
of many years experiment. If properly 



made it will run daily for months without 
deterioration. The spark takes place be- 
tween two pieces of brass rod 1%." diam. 
and 3^4" l° n g, turned and tapt as shown. 
The sparking surfaces are turned in an- 
nular grooves with a 60 degree tool. If 





Fig. 1. View of the Strong Conical Oudin 
High Frequency Coil Delivering a Veritable 
Tree of Sparks Several Feet in Length. 



Fig. 2. Another View of the Strong High 
Frequency Coil Producing a Perfect Sheet of 
Flaming Sparks to a Grounded Conductor. 
The Exciting Energy Is but 1 Kilowatt. 



throw off disease. This vitalizing effect is 
not due to the mere liberation of heat in 
the tissues, for it is produced by the very 
high-voltage ( "Tesla") currents as well as 
by the heavy amperage ("D'Arsonval") cur- 
rents from which the thermic effects are 
usually obtained. 

When the writer demonstrated the first 
therapeutic Tesla Coil and the first Vacuum 
Electrode — (in 1896 before a Boston Medi- 
cal Society) — and suggested that this meth- 
od was destined to come into general use 
as a vitalizing agent, he was laughed at by 
his colleagues ; yet to-day there is scarcely 
a well equipt physician's office in this coun- 
try or in Europe that does not contain some 
form of therapeutic high-frequency appa- 
ratus. Even the barber-shops of the pres- 
ent time have their small "Violet Ray" out- 
fits ; and these are not by any means "fakes" 
for they produce real results, such as the 
relief of headache, neuralgia, skin diseases, 
et cetera. 

Unlike other forms of electricity, these 
currents may be administered to patients 
with perfect safety. In twenty years' ex- 
perience in electro-therapeutics the author 
has never known of harmful results from 
the use of Tesla Currents applied thru a 
vacuum electrode. The heavy amperage 
("D'Arsonval") currents, owing to their 
deep thermic effects, should be used only 
under the direction of a physician. The 
writer is a firm believer in the use of 
Tesla currents in the home — if each mem- 
ber of the family could receive ten-minute 
daily treatments from a small high-fre- 
quency apparatus, the general standard of 
health would be greatly increased. This 
has been demonstrated in hundreds of cases. 



Conical 
Oud/n Co/l 




f/g.6 



Details Are Given in This Article for Con- 
structing a Reliable and Powerful Oudin op 
Tesla High Frequency Coll, Suitable for Phy- 
sicians' Use. This Type of Coil is the Most 
Efficient Ever Designed. 



your lathe has an automatic cross-feed you 
may set it to twenty turns to the inch, 
and turn a spiral groove instead of the 
annular rings. After finishing, the brass 
pieces are heavily silver plated and mounted 
in the usual manner as shown. (Fig. 4.) 
For currents over J4 K.W., a plate of silver 
should be soldered to the brass before turn- 
ing the grooves. This gap will also give 
greater efficiency in wireless work as com- 
pared with the usual stationary gap. 

The connections for the various parts of 
the apparatus are shown in Fig. 5. An 
important feature is the use pf an external 
inductance or tuning coil "d" in series with 
the Tesla coil. It consists of 32 turns of 
No. 8 bare copper wire, wound on a frame 
8" diam., with J4" between turns. Edge- 
wise wound flat copper strip is better- but 
more expensive. (d Fig. 8.) This coil 
when used in series with the Tesla primary 
enables us to tune the oscillating system 
in perfect resonance when the capacity of 
the patient's body is added to the Tesla 
terminal. Effects are produced which are 
impossible with any other method. The 
beautiful High-frequency Effluve or brush- 
discharge, so valuable in treating pulmonary 
diseases, and which so few modern high- 
frequency machines can produce, is obtain- 
able by the use of this series inductance. 
It may also be used, by short-circuiting the 
Tesla primary, as an auto-transformer from 
which may be derived heavy "D'Arsonval" 
and "Diathermic" currents as described in 
the next article of this series. 

For stage demonstration and public lec- 
ture work the writer employs a large high- 
frequency resonator which produces a tree- 
(Continued on page 59) 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



25 



Experimental Physics 



Instructor 

LESSON FOUR 
GASES AND THE ATMOSPHERE 
(Concluded) 

AIR expands when heated and be- 
comes lighter in weight. If we 
have a confined bodv of air such 
as in a room, for example, and 
there is a source of heat in the 
room, the air near the source will expand 




Simple Apparatus Comprising Box, Candle 
and Two Lamp Chimneys for Demonstrating 
the Principle of Ventilation. 

and become lighter and the heavier air at 
the top of the room will fall, forcing the 
lighter air upward. Thus it is that the air 
near the ceiling is always warmer than 
that near the floor. This shows the ne- 
cessity of opening a window at both the 
top and the bottom for best ventilation. 
EXPERIMENT 19— 

Fig. 15 shows very simple apparatus 
which can be made with practically any 
material available, for demonstrating the 
behavior of air near a source of heat. 
C, is a box thru which holes have been 
cut to admit tubes (or glass lamp chim- 
neys) B. A is a lighted candle. The 
arrows show the direction of the current 
of air. 

EXPERIMENT 20— 

An interesting experiment giving sur- 
prising results and having a simple ex- 
planation can be performed by the use of 
a spool and a visiting card. (If no visit- 
ing card is available, the ace from a poker 
deck which you may have "up your sleeve," 
will do very well.) Place the card up 
against the bottom of the spool as in Fig. 
16-A and the mouth against t e top of the 
spool. Blow vigorously and then let go 
of the card. One would naturally expect 
that blowing against the card would blow 



Closed/ 
end 



Closed; • 
end 



Open 
end Y 



Fig. /<? 



A Glass Tube, Sealed at One End and Filled 
with Mercury, Will Support a 30-inch Column 
of Mercury, Owing to Atmospheric Pres- 
sure Acting Against a Vacuum. The Prin- 
ciple of the Barometer. 

it away whereas actually the card stays 
fast, close to the bottom of the spool. 
Sometimes, when the conditions are not 



By JOHN J. FURIA, A. B., M. A. 

in Physics and Science Master, Riverdale Country 

just right; the card slides off perpendicular 
to the direction in which one blows, but 
to avoid this a pin should be stuck thru 
the card's center and then into the hole in 
the spool (care being taken not to stick 
it into the wood of the spool). Fig. 16-B 
shows diagrammatically what happens. The 
air from the mouth passes down the hole 
in the spool and out along the upper sur- 
face of the card. It is a well-known fact 
that the pressure is greatest where the 
speed is least and vice versa. The air 
underneath the card is practically still, 
while that just above the card is in rapid 
motion, and hence the pressure against the 
card from beneath is greater than that 
from above. Hence the card tends to get 
as close to the spool as possible and does 
not fall. 

EXPERIMENT 21— 

In the First Lesson we learned that at 
any depth in a liquid there is a pressure 
due to the weight of the liquid above that 
depth. We also learned that air has 
weight and consequently we conclude that 
the air (at the surface of the earth) has 
pressure due to the weight of the air above 
it. The higher up we go, the less air 
there is above us and hence the pressure 
is less. If one sucks in at the stem of a 
pipe (see Fig. 17) at the bowl of which 
is stretched a piece of sheet elastic, the 
pressure of the air above it pushes the 
elastic down. Suction is not a mysterious 
force ; it is simply a removal of the air 
from one side so that the pressure from 



/"^ fosifiol) of elastic 

• ■/ fop sheet wlii/e sucA/i/g 

L / out the air 

^ ill F >9- 17 



Removing the Air Within a Pipe Bowl by 
Sucking In Thru Stem Allows the Pressure 
of the Air to Push Elastic Diafram Inward. 

the other side can act without being op- 
posed. Actually, when the air is entirely 
removed from the pipe, the pressure above 
the elastic sheet is fifteen pounds on .each 
square inch; i.e., the weight of the col- 
umn of air from the earth's surface 1 the 
end of the atmosphere on each square 
inch of the earth's surface is fifteen pounds. 
A column of water thirty-three feet high 
and one inch square weighs fifteen pounds 
and a column of mercury thirty inches 
high and the same area, weighs the same 
(mercury weighs 13.6 times as much as 
water) . 

EXPERIMENT 22— 

Seal one end of a narrow tube having 
a diameter of about one-quarter inch and 
about fifty inches long. Fill the tube with 
mercury and invert it carefully and place 
the open end in a cup containing some 
mercury. The mercury in the tube will 
fall until the height of the mercury in the 
tube is about thirty inches above the level 
of the mercury in the cup. The same 
level is kept no matter how long and how 
wide the tube is. The air pressure on the 
cup's surface acts against the mercury in 
the cup and it is transmitted thru the mer- 
cury to the open end of the tube. Since 
the tube was filled with mercury and there 
was no air at the sealed end, we get the 
same effect as if air was there originally 



School 

and was sucked out; i.e., there is no air 
pressure in the tube and the air pressure 
outside can hold up the mercury to a level 
of about thirty inches. If now the seal 
is broken the air rushes in and the mer- 
cury in the tube falls into the cup. (See 
Fig. 18-A.) The pressure of the atmos- 
phere changes from place to place and 
from time to time. It is, therefore, im- 



Fig. 16 






* Card 
/ 


Spool* Yr^, 




. / 




R Pi 



If You Blow Down Thru the Spool the Card 
Sticks to the Spool, Contrary to General 
Opinion. 

portant to measure the exact pressure at 
each locality. It is possible to determine 
one's height above sea level by the read- 
ing of the barometer. Also the readings 
of the barometer show how the weather 
conditions are. The barometer is nothing 
but an instrument to measure the pressure 
of the atmosphere. Obviously our Fig. 
18-A represents a crude barometer. Its 
great disadvantage is that when carried 
about from place to place one is likely to 
spill the mercury. An improved form is 
shown in Fig. 18-B. The same tube used 
in A is sealed again, bent at the open end 
and filled with mercury. The air pressure 
acting at the open end supports a column 
in the closed end, so th^t th. height in the 
closed section is thirty inches above the 
level in the open end. In the commercial 
form a scale (yard stick) - attached so 
that one can read the levels directly. This 
form can be carried about more freely 
without danger of spilling the mercury but 
is nevertheless cumbersome and inconven- 
ient. The aneroid barometer is much more 
compact (it can be had even as small as 
an ordinary alarm clock). Instead of mer- 
cury to be acted upon, this instrument em- 
ploys a diafram which is moved in and 
out by the atmospheric pressure just as the 




A Simple Air Thermometer — Utilizes the Ex- 
pansion of Air on Heating to Vary the Height 
of a Water Column. 

sheet elastic was in experiment 21. The 
motion of the diafram is magnified by a 
system of levers and is communicated to 
(Continued on page -47) 



26 



THE ELECTRICAL EXPERIMENTER 



May, 1917 




Wireless Telegraphy 



General Superin 

THE history of wireless telegraphy 
repeats once more the old story 
that is so often connected with 
great inventions. The world be- 
ing possest of a new scientific 
principle, many minds in many parts of the 
world are simultaneously bent upon its 
practical application, with the result that 
the fundamental principle finds embodi- 
ment in various methods of accomplishing 
a similar purpose. The startling nature 
of the discovery of electric waves was 
bound to give rise to unprecedented activity 
in the field of experimental investigation, 
and such experiments as were particularly 
successful were bound to prompt investi- 
gators to seek patent protection on their 
modifications, and this in turn gave rise to 
several systems of radio-telegraphy. 

A voluminous list of names could be giv- 
en of those who have contributed to the 
advancement of radio-telegraphy in regard 
to both theory and practise. Among the 
best-known American investigators are Fes- 
senden, Shoemaker, de Forest, Clark, Stone 
and Massie. Each of these men f as devised 
a system which bears his name. In Eng- 
land the work has been carried on by men 



By E. B. PILLSBURY 
tendent, Marconi Wireless Telegraph Company of America, New York 

of such unqualified dis- 
tinction as Lodge, Alex- 
ander, Muirhead, Flem- 
ing, Thomson and Ruth- 
erford. Slaby, Arco and 
Braun are the names best 
known in Germany. The 
French are represented 
by Ducretet, Branly, 
Rochefort and Tissot, be- 
sides other men of lesser 
fame. Italy has contrib- 
uted largely to the sub- 
ject, principally thru 
Marconi, Bellini, Tossi 
and Righi. Denmark is 
represented by Poulsen. 
Spain, Austria, Bel- 
gium and Argentina have 
all produced systems 
which have been more or 
less used in their respect- 
ive countries. The Jap- 
anese have also devised a 
system that successfully 
stood the test of service 
in the Russo-Japanese 
War. 





Interesting View of a Bank of High-speed, Automatic Sending 
Keys and Bus-bar Connections in a Typical High-power Marconi 
Radio Station. 



Gigantic Oscillation Transformers and Tuning Inductances In 
Marconi Trans-oceanic Wireless Transmitting Station. 



The development of. 
the art in the various 
countries has been car- 
ried on largely by repre- 
sentative investigators, 
and in many instances 
the governments have 
adopted a system ex- 
ploited by their subjects. 
The United States gov- 
ernment, however, has 
experimented with most 
of the prominent systems 
offered, and, as a result, 
the army and navy equip- 
ments are comprised of 
quite a variety of appa- 
ratus of different inven- 
tors. 

Wireless telegraphy 
was the subject of ear- 
nest experimentation as 



early as 1838, but, as far as the public mind 
is concerned, the science began when Mar- 
coni sent his first message across the At- 
lantic from Cornwall to Newfoundland in 
1902. This wonderful accomplishment had 
so much of the spectacular element in it 
that wireless telegraphy and Marconi be- 
came famous at once and, measured by re- 
sults, he has eclipsed all other inventors. 

Marconi first interested himself in the 
problem of wireless telegraphy in 1895. In 
the following year he took out the first pat- 
ent ever granted in England for a practical 
system of wireless telegraphy by the use of 
electric waves. In 1897 he successfully 
communicated across Bristol Channel, a 
distance of nine miles. At the invitation of 
the Italian government, Mr. 'Marconi sub- 
sequently went to Spezia, where his system 
was put to practical test on board two It- 
alian battleships. A station was erected on 

'International Cable Register Supplement. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



27 



land, and the ships were kept in constant 
telegraphic communication with the shore 
up to a distance of twelve miles. Return- 
ing to England he made further experi- 
ments and succeeded in communicating be- 




Looking Up One of the Towering 450- Foot Tub 
Masts, Which Support the Immense Aerials Used 
the Ocean-wide Signaling Spans. 

tween Salisbury and Bath, a distance of 
thirty-four miles. 

Mr. Marconi came to the United States 
in 1899, in connection with the America 
yacht cup race between Columbia and 
Shamrock I, In the same year a number 
of ships of the British navy were equipt 
with his apparatus. Early in 1901 tele- 
graphic communication was established be- 
tween two points more than 250 miles dis- 
tant. In February, 1902, he received, on 
board the steamship Philadelphia, in the 
presence of the ship's officers, good mes- 
sages on a recording tape when at a dis- 
tance of over 1,500 miles from the trans- 
mitting station. In December, 1902, he es- 
tablisht a station at Cape Breton for trans- 
atlantic service, and maintained communi- 
cation with the Cornwall station at Poldhu, 
transmitting inaugural messages to the 
King of England and the King of Italy, 
the London Times . and others. A year 
later, during the voyage of the steamer 
Lucania, Mr. Marconi maintained commu- 
nication between the ship and the Marconi 
station at Glace Bay, in Cape Breton, and 
Poldhu, in England, and a newspaper was 
publisht and issued daily to each passenger. 
A powerful station at Clifden, on the west 
coast of Ireland, was opened early in 1907, 
by means of which public communication 
across the Atlantic was establisht, which 
has been maintained ever since. 

The importance of wireless equipment of 



sea-going vessels has been recognized by 
all nations, the United States law requiring 
two licensed operators on any ship carry- 
ing fifty or more persons and sailing be- 
tween ports 200 or more miles apart. It is 
estimated that upward of 5,000 
ships are now equipt, and a 
large number of freighters car- 
ry wireless for their own pro- 
tection, altho not required to 
do so by law. In fifteen years 
wireless has placed to its cred- 
it the saving of thousands of 
lives and property valued at 
several millions of dollars. It 
is an inestimable boon to man- 
kind that we can go to sea with 
the knowledge that we are kept 
in touch with home and can 
summon aid in case of disaster 
by means of the S. O. S. signal. 

Radio-telegraphy is a most 
potent factor for naval, mili- 
tary and airship use in the pres- 
ent war. On July 30, 1914, 
five days before the actual dec- 
laration of war, the English 
fleet, which had just left Port- 
land, was recalled by wire- 
less ; and on August 4, 1914, 
Germany flung around the 
world on its chain of wireless 
stations this vital message to 
its mercantile marine : "War 
declared on England ; make as 
quickly as you can for neutral 
port." This first dispatch un- 
questionably saved Germany 
many millions of dollars of 
property and secured for pos- 
sible future use a fleet of pas- 
senger and cargo boats which 
may yet play a great part in 
her recovery from war's rav- 
ages. 

As long distance wireless 
rang up the curtain on the 
greatest war the world has yet 
witnessed, so it has continued 
to play a great part therein. 
One of the most striking points 
in connection with wireless, 
which has been developed by 
the war, is that public attention 
has been directed upon it as 
never before, owing to the fact 
that so much of the official communications, 
particularly German information, has been 
brought to the notice of newspap_er readers 
thru this medium, owing to obstruction of 
the German cables. 



ular Steel 
to Bridge 



One of the objections made against wire- 
less telegraphy is in regard to the possi- 
bility of interference between various sta- 
tions and the confusion likely to arise when 
a number of stations are simultaneously 
operated in the vicinity of one another. 
Altho this confusion does rarely arise in 
practise with proper up-to-date stations and 
apparatus, yet even with the old instruments 
when it did occur it was not by any means 
such a serious matter as generally appeared 
to the imagination of the public. In most 
countries the operation of wireless tele- 
graph stations in regard to ship and shore 
communication is subject to judicious rules 
tending to prevent mutual interference. It 
is well known that without proper organi- 
zation and discipline,, serious difficulties 
due to interference would occur with the 
great majority of ordinary land wire tele- 
graphs which work several offices by means 
of a single wire. In the case of wireless 
telegraphy it is often an advantage that any 
station should be able to pick up a mes- 
sage which may not be actually addrest to 
it, as, for instance, in the case of a ship in 
distress calling for assistance. The most 
practical method of isolating any particular 
receiver so as to make it sensitive only to 
signals coming from a certain station lies in 
the principles of resonance; that is, to tune 
the sending and receiving circuits in exact 
correspondence. 

When the war broke out a German com- 
pany had high-power stations in commu- 
nication between Sayville, L.I., and Nauen, 
Prussia (3,262 miles), and between Tuck- 
erton, N.J., and Eilvese, Prussia (3,383 
miles). In order to protect our neutrality 
the American government took over these 
stations and is now operating them in the 
interests of the owners. 

The government has erected a high-power 
station at Arlington, within sight of the 
Capitol at Washington, with a radius of 
3,000 miles under ordinary conditions. It 
represents the first step of the Navy toward 
the establishment of a great chain of high- 
power wireless stations to girdle the earth 
and bring the Navy Department into direct 
communication with the fleet thruout the 
length and breadth of the seas. Unless a 
war vessel be in the Arctic, Antarctic or 
Indian Oceans, it will be at all times with- 
in the range of one of the seven contempla- 
ted stations, the other six of which are to 
be located at San Francisco, Honolulu, Ma- 
nila, Guam, Panama and Samoa. 

From the Arlington station messages can 
be sent to vessels stationed beyond the 
{Continued on page 77) 




500-horsepower Steam Turbines and Generators in Marconi Trans-oceanic Radio Station. 



28 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



San Diego — Largest Radio Station in U. S. 

By J. BASSETT 



THE new $300,000 wireless telegraph 
station at San Diego, Calif., has just 
been completed and officially put in 
commission January 26, 1917. It is the 
largest and most powerful radio station in 
the western hemisphere. It is capable of 
flashing messages 12,000 miles. Messages 




three 100 kilowatt transformers 2,800 
pounds each. 

Establishment of a distant control sys- 
tem will enable operators at any naval ra- 
dio station on the Pacific Coast from Point 
Loma to Alaska to operate its sending in- 
struments. This is accom'plisht by a sys- 
tem of land telegraph lines. The 
radio apparatus is what is known 
as the Federal Poulsen arc trans- 
mitter and was manufactured by 
the Federal Telegraph Co., of 
San Francisco. The Poulsen arc 
employs a direct current arc of 
600 to 1,000 volts, burning in a 
closed chamber of hydrogen, the 
terminals being placed at right 
angles in a powerful magnetic 



View Above Shows Mission Style Operating 
Building and Fan-Tail Lead-in at Powerful New 

U. S. Radio Station, San Diego, Cal. 

At Right: — Looking Up One of the Gigantic 600- 
Foot Latticed Steel San Diego Wireless Towers. 
Below: — Concrete and Porcelain Base Support 
for Insulating the Steel Tower Legs. 





from the British high seas fleet cruising 
in the North Sea, from the high powered 
German plant at Berlin and from Aus- 
tralia have been intercepted thus far. 

The three 600 foot aerial towers form 
a triangle. They contain one million 
pounds of fabricated steel and are the 
largest radio towers in the world. The 
towers are triangular in section, 150 feet 
in width at the base and eight feet at the 
apex. They are placed 1,100 feet apart. 
Porcelain insulators imbedded in concrete 
form the base of each leg of the towers. 

The receiving room is absolutely sound 
proof, the walls and floor being padded 
with asbestos. There are four distinct 
and complete controlling sets installed in 
the receiving room, enabling any one of 
the four operators or all four at once to 
send and receive messages. 

The aerial or antennae weigh 16 tons 
and has a sag between towers of 100 feet. 
The aerial is twice as large as that strung 
from the Eiffel Tower in Paris. The 
helix is 14 feet in diameter and 11 feet 
in height or 9 feet higher than the helix 
used in ordinary naval and commercial 
stations. 

The generator weighs 60 tons and the 



field. Electric current for the 
radio set is furnished by a 200 
kilowatt — 1,000 volt direct cur- 
rent generator, driven by a 300 
horsepower 2,200 volt 60 cycle in- 
duction motor. 

Six buildings costing $39,590, 
in mission style architecture, 
form the quarters for those on 
duty. Here we find a large, airy 
dormitory, gymnasium and well- 
furnished library. 

A silver plated telegraph key was pre- 
sented to Commander Hooper after he had 
dispatched the first message. The fol- 
lowing inscription was on the key : "High 
Power Radio Service, First Message, 
Com'd'r S. C. Hooper, Jan. 1917, San Die- 
go." At exactly 11.02 January 26, 1917, 
Commander Hooper called the station at 
Arlington and sent this message from the 
Mayor of San Diego to Secretary J. 
Daniels : 

"In behalf of the citizens of San Diego 
I have the honor of extending to you the 
season's greetings and their good wishes 
and congratulate you upon the completion 
at San Diego of the world's most power- 
ful radio station. Space has been com- 
pletely annihilated and the Atlantic and 
Pacific seaboards are as one." 

Arlington acknowledged the message at 
11.05 o'clock. It was immediately trans- 
mitted by telephone to Secretary Daniels. 
His reply was returned at 11.18. It was 
thus : 

"Your greetings and congratulations 
much appreciated. The navy department 
rejoices with San Diego that the comple- 
tion of the new radio station at San Diego 



places Washington in closer touch with 
the Pacific Coast and particularly with the 
navy's larger development at San Diego. 
It must be gratifying to California to 
know that the apparatus installed is the 
product of a California company." 

This was followed by a message from 
Congressman Kettner. It was as follows : 
"Washington salutes San Diego, first port 
of call by wireless. Felicitations extended 
thru you to people on completion of the 
greatest radio station in the United States 
made possible by your esteemed friends, 
Secretary Daniels and Admiral Griffin." 

It was answered by Howard Veeder, 
vice-president of the Federal Telegraph 
Co., as follows : 

"Please accept the felicitation of the 
Federal Telegraph Co. and myself person- 
ally upon the successful opening of this 
great radio station. It is a g%eat pleasure 
to our company that the first example of 
this most remarkable advance in the ra- 
dio art, which has been developed by us 
in San Francisco should be installed in 
San Diego, a sister city." 

The radio plant is located in a section 
called Chollas Heights, ten miles from 
the business center of San Diego, on an 
elevation of land, reached by auto. 

U.S. RADIO INSPECTORS USE 
CODE MACHINE IN TESTING 
APPLICANTS. 

All applicants for U. S. Government 
Radio Operator's License must pass a 
test in receiving messages in the tele- 
graphic code, i.e., in the form of dots and 
dashes. The accompanying illustration 
shows a new complete automatic tele- 
graphic code transmitter, known as the 
Omnigraph, complete with high-note buz- 
zer and exciting batteries, which latter 
are contained in the base of the cabinet. 
The various discs, which are properly 
notched on their periferies to correspond 
with the dots and dashes of the different 
letters of the alphabet, are placed one 
above the other on a rotatable drum or 
plate, which is driven by a strong spring 
motor provided with a suitable governor, 
in order that the discs may be caused to 
rotate at any desired speed. 

The toothed disc makes contact with a 
special light spring brush connected with 
the high-note buzzer circuit. Thus, as the 
discs slowly rotate, the buzzer circuit is 
made and broken in accordance with the 
long and short notches on the edges of the 
discs. 

This instrument has been used for a 
number of years by the government officials 
in examining applicants for Radio Opera- 
tor's License and has been found very sat- 
isfactory. The messages may be signaled 
with this apparatus at any speed from 12 




Automatic Code Apparatus Used by U. S. 
Radio Inspectors in Examining Applicants 
for Operator's License. 

words up to 30 words, or more, per min- 
ute, thus giving it a wide range of useful- 
ness. 

A large variety of code disc are available 
and the machine may be set up to give dif- 
ferent code combinations as often as de- 
sired. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



2<> 



WIRELESS OUTFIT ON MOVING 
VAN TRACES MESSAGE. 

After a search of three months for an The accompanying photographs show the 
amateur wireless operator who sent out long distance, undamped wave receiving 
unsigned "SOS" messages in the neighbor- set owned by Harvey L. Gamer, Electrical 
hood of New York and caused great an- Engineer of Omaha, Neb., with which the 
noyance to the New York Navy 
Yard and navy vessels the feder- 
al authorities recently arrested 
William F. Eckoff, sixteen years 
old, who had a wireless station 
on the roof of his home in 
Brooklyn. 

When the messages were first 
heard there were reports in ship- 
ping circles of submarines operat- 
ing near New York. After sev- 
eral of these calls stations near- 
by recognized them as the work 
of an amateur. The New York 
Herald's wireless station worked 
■with the operators at the New 
York Navy Yard in an effort to 
locate the station. The log at the 
Herald's wireless station shows 
that these distress messages were 
sent at all hours of the night. 
The mysterious operator used 
the calls of the Navy Yard and 
naval vessels. 

Louis R. Krumm, chief radio 
inspector of the Department of 
Commerce, engaged a moving 
van and installed in it a small 
wireless set which could detect 
messages within the radius of 
only a block. Operators had 
traced the messages to Brooklyn, 
and, with the moving van, Mr. 
Krumm went about Brooklyn un- 
til he arrived in front of the 
Court Street house. 

It is alleged that Eckoff used 
a United States code signal on 
the night of January twenty-first 
last, sending an "SOS" call which 
which was picked up by the Herald station 
and relayed to t e super-dreadnought Ari- 
zona at the New York yard. 

Eckoff was arraigned before United 
States Commissioner Louis Bick and ad- 
mitted he had been sending messages, but 
asserted that if he had used the United 
States code he had done it innocently, for 
he did not understand the code thoroly 
enough to commit a nuisance. 

The efficiency of such portable radio sta- 
tions has been markedly improved in re- 
cent years by the advent of spiral aerials. 



An Exceptional Amateur Radio Station 



The amplification feature is obtained by 
the use of inductances and capacity in the 
wing circuit of an Audiotron, then a 
further amplification with two ordinary 




Above: — General View of Ex- 
tremely Efficient Experimental 
Radio Station Owned by Harvey 
L. Gamer, of Omaha, Neb. Note 
Phonograph at Right of Photo; 
the Signals are Recorded on it. 



Upper Right View Shows the 
Well Designed Antenna Used 
With the Apparatus Here Illus- 
trated. 

Lower Right: — Close View of 
15,000 Meter Precision Loose 
Coupler and Audion Tuning In- 
ductances. An Engineer's Idea of 
How an Amateur Station Should 
be Built. 



German Stations OUI, 
(Hanover), POZ, 
(Nauen) and the Hono- 
lulu Station KHL, are 
easily heard. 

Some of the stations in the United 
States, WSL (Sayville), and especially 
WGG (Tuckerton), when the Goldschmit 
alternator is used, come in so loud that 
the signals can be transmitted over the 
telephone to any part of the city or vicin- 
ity. Also wax phonograph records have 
been made with a special recorder, as 
shown in the photograph. 



Audions and their respective coils and cir- 
cuits as well as a micro-phone arrangement 
leading to the recording machine. 

The large loose coupler was designed to 
tune to wave lengths up to 15,000 meters 
when used with this particular aerial sys- 
tem. 




SECRETARY OF COMMERCE 
SUSPENDS ISSUING OF LICENSES 

Issuing of licenses for amateur wireless 
apparatus was suspended on March twenty- 
seventh by Secretary Redfield. Virtually 
none of the amateurs have sending equip- 
ment, so the military and naval authorities 
have not considered them a source of im- 
mediate danger, but Mr. Redfield decided 
that no more should be licensed for the 
present. Sending wireless plants are under 
the strictest possible surveillance now, and 
if a state of war is declared efforts will be 
made to locate apparatus of every descrip- 
tion. 

Many of the amateurs now licensed by 
the Government belong to the Navy radio 
reserve and will be called upon to perform 
certain duties in war. 



Uncle Sam's Radio Inspectors Find it Difficult at Times to Accurately Locate and Run Down 
Stations which Disobey the Law, but a Radio Set and Aerial Erected Inside an Auto Van 

Helped to Solve One Problem. 



TO TEACH GIRLS WIRELESS 

At a meeting of the National Special 
Aid Society recently, a school offering a 
course in wireless telegraphy for young 
women was organized. Instruction will 
be given at the society's headquarters, 259 
Fifth Avenue, New York Citv. 

Miss Daisy Florence, chairman of the 
new branch, urges that all young women 
who would like to take up this class of 
work send in their applications. E. T. 
Bicak, a New York radio expert, has been 
retained and will have entire charge of the 
classes. This new department, the society 
says, is the first of the kind. 



30 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



How the Audion Repeater Repeats 

A Twentieth Century Fairy Tale, Wherein the Mystery of the Audion Relay 
Is Explained for the Benefit of Radio "Bugs" of All Ages — From 9 to 90 



YOU all remember what you learned 
at school about matter being made 
up of molecules and molecules 
being made of atoms beyond which 
matter is indivisible. That is, 
with a meat axe, you can divide a sub- 
stance into small pieces like hash ; and with 
a microscope and hair-splitting equipment 
you can divide a substanc into pieces 
smaller than the naked eye can distinguish ; 
after that by means of chemicals you can 
separate molecules from eac' other altho 
you can't see them, even with a microscope ; 
then with more chemicals you can separate 
the atoms from each other, but beyond 
this no treatment has any effect ; at least 
that's what we learned at school and that 
effectually proves that there are no such 
things as fairies or daemons. 

But now come our highbrows with an- 
other story. Mind you, you don't have to 
believe it. They say that atoms 
may be made to throw off par- 
ticles like a small boy throwing 
gravel at the passing trolley car, 
only the kiddies do it voluntar- 
ily for the fun of the thing, 
whereas the atoms must have 
some provocation ; for example, 
if they get good and hot they 
cqmmence to throw gravel like 
a, terrier pup at a woodchuck 
hole. 

Now, all ordinary people 
know how to take such talk as 
this. It's just like Arabian 
Nights and Dr. Cook stuff about 
stones talking and mountains 
splitting open, or the beautiful 
stripes around the North Pole. 
Nevertheless one of our cloister 
experts will draw you a picture 
like Fig. 1, to represent the in- 
terior of a vacuum bulb repeat- 
er, and says that "F" is a fila- 
ment, which is heated red hot 
by the electric current from bat- 
tery "A," and "P" is a plate 
which is connected to the out- 
going line. In the space be- 
tween the filament and the plate 
is the piece of picket fence 
"G," which is connected to the 
incoming line, and this gridiron 
is what puts the fire in amplifier. 

To make the matter perfectly 
clear, as a fairy tale should be, 
look at Fig. 2, where 7 instead of 
a filament there is an iron step- 
ladder on which you can see a 
lot of atoms, or daemons — it 
doesn't matter which you call 
them — and on the other side you 
see the plate as in Fig. 1. Be- 
tween these two is an ordinary 
window blind with slats which 
are all operated together by the 
usual center stick. Now, suppose 
a strong electric current is past 
thru the iron stepladder so that 
it heats up like the filament in 
Fig. 1, then each little daemon 
gets as mad as a hen on a hot 
griddle and begins to throw 
pebbles at the window shutter. 
What's that ! Where do they get the peb- 
bles? Say, this is a fairy story and you 
must not ask foolish questions. Lord 
Kelvin thought the atoms were made of 
these pebbles or corpuscles, and that 
these pebbles or corpuscles were, in fact, 
electricity itself, hence the name electrons. 
In other words, matter is made of electricity 
and electricity is imponderable; therefore, 
there is no matter, and if there is no matter, 



it doesn't matter, and we should worry. 

If while the daemons are bombarding 
the shutter we should open the slats, 
enough pebbles would go thru and strike 
the plate to make a noise like a hailstorm 
on a tin roof and the number that strike 
the plate would be in proportion to the 
amount the slats are opened. Therefore, 
if the slats are opened and closed in time 
with music it would be possible to play a 
tune on the plate, and if each electron 
carried a little bit of electricity with it, 
the effect would be like a current from 
the stepladder to the plate, and this cur- 
rent would pulsate, increasing when the 
slats are opened and decreasing when they 
are closed. 

This is just what happens in the vacuum 
repeater bulb shown in Fig. 1. The filament 
is heated red hot by the current from 
battery "A," and" at this temperature mil- 




The Above Illustrations Help to Make Clear in the Most Simple 
Manner, the Action of the Audion — That Mysterious Radio-elec- 
trical Device. Considering the Top View, Just Imagine That the 
Host of Daemons on the Ladder (the Filament) Start Throwing 
Pebbles Thru the Movable Slats (the Grid) at the Target (the 
Plate). How Do They Get the Pebbles? — Oh! Well — Read This 
Remarkable Tale. 

lions of corpuscles or electrons are thrown 
off. The electric current is not necessary 
to cause this ; the same thing would hap- 
pen if it were heated by a gas flame. 
These electrons are considered to carry 
charges of negative electricity itself. Here 
again we should worry, because the result 
is the same, no matter what anyone thinks ; 
because a current actually does flow from 
the filament to the plate. 



You all remember that unlike polarities 
of electricity attract each other while like 
polarities repel, and so if the gridiron is 
made negative to the filament the electrons 
will be repelled by it and very few will 
get thru between the slats; in fact, if the 
slats are too close together no electrons 
at all will get thru to the plate. The ef- 
fect would be the same as tho the slats in 
Fig. 2 were entirely closed. 

It is generally known how the sound 
waves produce electrical pulsations in a 
telephone line; and you have only to im- 
agine these pulsations of current coming 
to the induction coil "T" at the left side 
of Fig. 1. These pulsations are, of course, 
very weak because of the long line over 
which they have traveled and the purpose 
of the repeater is to amplify or strengthen 
these pulsations. 

Now, while it takes considerable power 
to open and close the slats of 
a window blind, especially if 
you painted them yourself last 
spring, the operation of the 
electric shutter is frictionless 
and even the weak impulses of 
speech transmitted over 500 
miles of line are sufficient to 
give the desired results so that 
as each increase or decrease of 
current raises or lowers the 
negative potential of the grat- 
ing "G," more or less electrons 
each with its infinitesimal 
charge of electricity get thru 
from the red-hot filament to the 
plate and give the exact same, 
but much stronger, impulses of 
current from the plate to the 
induction coil at the right side 
of the picture, and so out on 
the line for another 500 miles, 
the amount ■ of additional pep 
put in the impulses, depending 
on the strength of the battery 
"B." 

Now you are probably won- 
dering why this apparatus is put 
in a glass case. The reason is 
that the scheme will only work 
in a very good vacuum because 
a clear space is necessary for 
the electrons to travel in. You 
must remember that everything, 
even an invisible gas, is com- 
posed of atoms, so if there was 
air or any kind of gas in the 
space between the filament and 
the plate, the electrons would 
bump the atoms of the gas 
while the daemons might put a 
good many across, the number 
would not be constant from 
minute to minute, depending on 
how successful they were in 
dodging the atoms and the re- 
sult of this would be a jerky 
current which would entirely 
mask the telephonic pulsations. 
Therefore, in order to obtain 
the required accuracy of con- 
trol of the rate at which the 
electrons strike the piate, it is 
necessary to pull out of the 
space between the filament and the plate 
every loose atom that it is physically pos- 
sible to get hold of. , 

This is so important that our highbrows 
have developed an extremely interesting 
method of inducing daemons themselves to 
call the game when the space is cleared, 
but that is another story to be told when 
you have recovered from this one. — 
'"W.E.N." 



May, 1917 THE ELECTRICAL EXPERIMENTER 3 

The Ionic Radio System and Theory of Ionic Tuning 

By Otto E. Curtis 

Associate Member ot the Institute of Radio Engineers 



THE physico-chemical science per- 
taining to the elemental constitu- 
tion of matter and the relation of 
the ion to the organization of 
matter dates back to the time of 
Thales of the so-called "early school of 
Ionic Philosophers," which came into exis- 
tence about six centuries ii'.C. Thales, and 




The Apparatus Used in Ionic Tuning of 
Radio Messages According to the Method of 
Mr. Curtis, as Described Herein. 

the other scholars of this time, made little 
real progress toward a scientific develop- 
ment of the subject, altho in the light of 
recent discoveries many of their heretofore 
seemingly crude experiments and theories 
'appear to have surprising significance. 

For example, the ancient Alchemists of 
this period made many attempts at "trans- 
mutation," that is, at converting basic met- 
als such as lead into precious metals such 
as gold, and in connection with these ex- 
periments they developed theories which, 
while entirely too vague to lead to useful 
conclusions, bear similarities to the modern 
theories pertaining to tne transmutation or 
transformation of various radio-active com- 
positions of matter into other comoounds 
having different ionic groupings. Howev- 
er, the secrets pertaining to the part played 
by ions in the constitution of matter have 
not, at least up to the present time, been 
discovered and subjected to the use of man. 

During the past eleven years I have been 
continually striving to fathom some of these 
secrets and it is my present purpose to dis- 
close one of the more important discoveries 
which has resulted from my investigations, 
this particular discovery forming the ba- 
sis of one of my earlier patent applications. 
And in order more clearly to set forth this 
discovery I ^hall first describe some of my 
experiments and the apparatus employed. 

The first machine I built with the object 
of recording messages was completed in 
1906. It consisted of an E. I. Co. "Auto- 
coherer" connected to a "Telimco-meter" 
galvanometer with contacts on the needle. 
Impulses received by the auto-coherer were 
intended to deflect the needle and close 
relay contacts, but they did not do so and 
this machine failed to operate. This was 
an attempt to find a self-restoring coherer, 
but, while the coherer was self-restoring, 
it was not sufficiently responsive to current 
of the magnitude which I then employed. 

A later machine, completed November 
25, 1916, and shown in the accompanying 
photograph, follows the same original idea 
but its special parts have been much more 
highly developed. It receives perfectly the 
time from Arlington at a distance of 200 
miles, ticking it off clearly on a buzzer and 
making tape records of the same, but as yet 

* Copyright 1917 by Roberts, Roberts and Cush- 
man. Exclusive rights to The Electrical Experi- 
menter. 



it is not quite fast enough to copy actual 
commercial messages. It was originally de- 
signed as a chemically tuned call-bell for a 
wireless telephone, for which it works ex- 
cellently. (This process of chemical tun- 
ing or Ionic tuning will be explained fur- 
ther on.) 

The apparatus illustrated in the photo- 
graph is made up as follows : The device 
shown in the upper left-hand corner is a 
Multi-audi-fone pocket wireless set. The 
wooden base in the lower left-hand corner 
carries two of my ionic detectors construct- 
ed as shown in Fig. 5, and as hereinafter 
described, the one on the left comprising a 
zincite crystal and the one on the right a 
silicon crystal. The rectangular instrument 
in the center is a Weston relay, which com- 
prises an extremely sensitive galvanometer 
having a very short needle which, when de- 
flected, contacts with one of the platinum- 
iridium points disposed on opposite sides of 
the needle. The instrument on the right is 
an E. I. Co. polarized relay of 1,000 ohms 
resistance which may be connected to an 
indicating or recording or other device such 
as a buzzer, tape recorder, motor, lamp or 
explosive device. 

In the accompanying figures, Fig. 1 shows 
the circuit connections for the apparatus 
shown in the photograph, the various instru- 
ments being diagrammatically illustrated in 
the figure in the same relative positions as 
in the photograph for the sake of clear- 
ness. The antenna 1 is connected to ground 
2 thru the primary 3 of the Multi-audi- 
fone set, the secondary 4, of which is ar- 
ranged to be connected to the Weston re- 
lay by means of double throw switch 5 
either thru detector 10 or thru detectors 
7 and 8. When the switch 9 is to the left, 



Diagram of Connections 
Possible to Realize the 
Claimed. Besides, 

the zincite detector 7 is connected in cir- 
cuit; when the switch 9 is to the right the 
silicon detector 8 is in circuit, the detectors 



7 and 8 being connected to the secondary 

4 by leads which arc not shown. The cir- 
cuit connections as existing when the switch 

5 is in upper position, are shown in simpli- 
fied form in Fig. 2, reference to which may 
be had in following out the operation. 

The alternating current of radio fre- 
quency received by the open antenna circuit 
1-3-2 is induced into the secondary circuuit, 
where it is rectified by the detector 10 and 
conducted to the Weston relay 6. This pro- 
duces a deflection of the relay 6 which in 
turn closes the local circuit containing the 
polarized relay 11 and source of e.m.f. 12. 
This actuates relay 11, which closes the 
circuit thru a second source of e.m.f. 13 and 
the indicating, recording or power appa- 
ratus 14. By employing one of my im- 
proved ionic detectors at 10, very feeble im- 
pulses may be detected ; and by employing 
a series of relays in the manner described, 
the feeble impulses may be magnified to any 
desired extent, each consecutive relay con- 
trolling a heavier current so that the last 
circuit 11-13-14 may comprise a power cir- 
cuit carrying current of any strength. 

When using the machine for lecture pur- 
poses, with the sender in the same room 
a "Hertz" lineal resonator is used instead 
of an aerial and ground, as shown in Fig. 
3. This consists of two l A inch brass rods 
fitted on adjacent ends with brass balls of 
equal size and separated a short distance, 
this distance bearing a direct ratio to the 
length of the spark gap of the sender. The 
free ends of the rods are fitted with the 
movable metallic plates 15. Moving these 
plates together with the similar ones on the 
oscillator of the spark gap tunes the sys- 
tem. This "resonator" serves the same pur- 



pose as the "catch wires" used on the E. I. 
Co. "Telimco Coherer Set." The resonator, 
(Continued on page 73) 




Used in the Curtis Scheme of Ionic Tuning, Whereby It Becomes 
Highest Efficiency in Radio Transmission and Reception, It Is 
It Enables the Operator to Record the Messages if Desired. 



32 THE ELECTRICAL EXPERIMENTER May, 1917 

Receiving Marconi 300 K.W. Spark Stations with Oscillating Audion 

By SAMUEL CURTIS, Jr. 



IT is a widely known fact that the 
Marconi Wireless Telegraph Com- 
pany has in operation a number of 300 
K.W. spark stations, used for the 
purpose of handling their enormous 
traffic between different countries. The 
stations of this character which are active- 
ly engaged, to my knowledge, in transact- 
ing business at the present time, are : Clif- 
den, Ireland; Glace Bay, Nova Scotia; Bo- 
linas, California ; Koko Head, Hawaii, and 
Funabashi, Japan. 

The wave length used in transmission 
ranges from 4,000 to 8,000 meters, but 
the most common is 6,100; this is used ex- 
tensively at the Koko Head and Bolinas 
stations. 

In receiving the signals from these sta- 
tions, any Audion receiver capable of at- 
taining the wave length may be used, and 
it may be well to state that the undamped 
wave receiver described on page 575 of the 
December issue of The Electrical Ex- 
perimenter has been used in this respect 
with marked success. The writer wishes 
to state, however, that since the publica- 
tion of his article relative to this receiving 
set, a fixt condenser of .005 m.f. has been 
added to the circuit. This is hooked up 
across the telephones and high potential 
battery of the Audion, and by its use al- 
lows the bulb filament to be burned at 
a much lower brilliancy, and yet get strong 
oscillations therefrom. 

It is, of course, easily possible to receive 
these stations on a crystal detector, but un- 
less an extremely large antenna is avail- 
able, .this cannot be accomplished over any 
great distance. It has been found by ex- 
periment that a heterodynic action on the 
incoming signals produces a remarkable 
increase in audibility, therefore making it 
feasible to incorporate the use of an os- 
cillating Audion in this respect. 

The series of graphs shown in Fig. 1 
clearly illustrate the character of the mo- 
mentary currents produced by a feebly 
damped wave train, in the circuits of a 
receiver during the process of heterodyn- 
ing. In graph "A" we have the feebly 




The Series of Graphs Shown Above Serve to 
Illustrate the Character of the Momentary 
Currents Produced by a Feebly Damped 
Wave Train, in the Circuits of a Radio 
Receiver During the Process of "Heterodyn- 
ing." 

damped wave train, such as is sent out by 
the above mentioned high-powered stations. 
In graph "B" we have the local or Audion 
oscillations, which are used in heterodyn- 
ing the wave train of graph "A." These 



Audion oscillations are tuned to a fre- 
quency either higher or lower than that of 
the incoming wave, so that an audible note 
is obtained in the telephones. In graph "C" 
we have an illustration of the current pro- 
duced after "A" and "B" have coincided 
with, or heterodyned each other. In graph 
'D" is shown the resultant current after 
it has been rectified. It should be under- 
stood that the tone of this current in the 
telephones is proportionate to the difference 
in frequency of the incoming wave, and the 
Audion oscillations; for instance, a wave 
length of 6,000 meters would have a fre- 
quency of 50,000 cycles. In order to get 
an audible note of 500 cycle pitch, we 
would have to have an Audion frequency 
or either 49,500 or 50,500 cycles. This is 
assuming that we are heterodyning an un- 
damped wave. Of course when a damped 
wave is heterodyned it cannot be expected 
that a pure note will be obtained, owing to 
its irregular form. In actual practise the 
note obtained in heterodyning the Mar- 
coni signals is very near the same as that 
obtained by using a crystal, only a little 
distorted. 

The beauty of the use of the heterodyne 
reveals itself in an astonishing increase 
in the amplitude of the telephonic current, 
as illustrated in sketch No. 2. It can be 
seen by observation of this sketch that the 
mere rectification of a wave train does not 
in any way amplify it. Now, .if the same 
wave train is heterodyned, an increase 
in amplitude similar to that illustrated in 
sketch No. 2 is obtained. The reason for 
this is best explained by the fact that in 
the mere rectification of a damped wave 
train, only the first few oscillations are 
utilized, and the rest of the energy is hope- 
lessly wasted. In subjecting a feebly dampt 
wave train to heterodynic action practi- 
cally all of the energy is utilized, mani- 
festing itself in an enormous increase of 
audibility. To those who are more or less 
familiar with the action of the heterodyne, 
this brief explanation will suffice, but to go 
into a detailed description thereof would be 
out of the scope of this article. 

It might be of interest for the reader 
to know that at the present time, at a cer- 
tain experimental station on the Atlantic 
Coast, signals are being received daily 
from the Marconi station at Koko Head, 
Hawaii. The receiver used is of the type 
described in the December issue of this 
journal with the single exception that an 
Electron Relay is used instead of the usual 
spheric Audion bulb for producing the os- 
cillations. Glace Bay, Nova Scotia, comes 
in with remarkable audibility, while Boli- 
nas, California, is read nearly as loud. The 
stations at Clifden, Ireland, and Funabashi, 
Japan, have not as yet been pickt up, but it 
is expected that in the near future Clifden 
will be copied, as this station is not nearly 
as far distant as Koko Head, who is read 
in the daytime in good weather. The 
aerial used at the above mentioned sta- 
tion has a natural period of 276 meters, 
and is none too elaborate. 

The results made possible by the oscil- 
lating Audion in receiving dampt waves are 
not however confined to such long waves 
as are used by the Marconi stations. With 
careful adjustments and the use of low 
resistanced inductances, an Audion can 
be made to oscillate on 200 meters or less, 
depending of course upon the skill and 
perseverance of the operator. 

No one can fully appreciate the efficiency 
of such a method of reception until he has 
actually used it himself. At the present 
time there are a number of Regenerative 
receivers on the market. These instru- 



ments are without a doubt the peer of any- 
thing in their line, but for many experi- 
menters the price of such an outfit is pro- 
hibitively high, and the chances are they 
have to do without. One advantage, how- 
ever, is that these receivers are not so in- 
tricately designed as to make it impossible 







































































































1 


\ 



















Fig. 2 



Graph Illustrating the Marked Increase in 
the Amplitude of Received Radio Signals 
Due to "Heterodyning" by Means of the 
Oscillating Audion. 

for the experimenter to make one for him- 
self. This is being done with great suc- 
cess by a large number of amateurs thru- 
out the country. If the reader cares to 
take the trouble to consult page 575 of the 
December issue of this magazine, he will 
see a neat little regenerative hook-up 
given in set "B" of the diagram on that 
page. Set "A" is used for long waves, 
and set "B" for waves from 200 to 2,500 
meters. 

[We are informed by Mr. Curtis that in 
some tests conducted in the laboratories 
of the General Electric Co., at Schenecta- 
dy, Dr. White has succeeded in making an 
Audion oscillate (heterodyne action) on a 
wave length as low as y 2 meter. Of course 
this requires some elaborate tuning and 
even more elaborate apparatus.— Ed.] 



RADIO EXHIBIT AT NEW YORK 
AERO SHOW. 

At the recent Aeronautical Exposition 
held in New York City, serious considera- 
tion was .given to radio equipments for 
aeroplanes and balloons. A large space 
was set aside for the exhibition of different 
types of sets, such as are used now in the 
European countries for directing the artil- 
lery from aeroplanes, for interfering with 
stations and for long distance communica- 
tion to be used by observers. Models of 
the different types of wireless equipments 
using direct and alternating current gener- 
ated by small dynamos which get their 
power from the air by means of a small 
propeller were shown. The Marconi Com- 
pany was invited to exhibit the set which 
was recently purchased by the Navy De- 
partment for hydroaeroplanes. This in- 
strument has one K.W. capacity and it is 
stated that up to 300 miles will be obtained. 
That is to say, the aeroplane can signal for 
a radius of 300 miles. The total installa- 
tion will come within 100 pounds. Other 
sets made by the Sperry Gyroscope Com- 
pany, De Forest Radio Telephone & Tele- 
graph Company; William Dubilier, Wire- 
less Specialty Apparatus Company, Cutting 
& Washington, Manhattan Electric Supply 
Company and Mr. A. B. Cole. The wire- 
less operators were supplied by the East 
Side Y.M.C.A. under the direction of Mr. 
Boehm. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



33 



Distributed Capacity and Its Effect 



D 



capacity 



ISTRIBUTED capacity may be 
defined as the capacity existing 
between turns of a helical coil. 
It may also exist in straight con- 
ductors where the electrostatic 
s between the conductor and the 




Theoretical Relation of Distributed Capacity 
to Inductance Coils. The Effect Is the Same 
As if a Number of Small Condensers Were 
Connected Across the Turns on the Coil. 

earth, or between two adjacent conductors. 

It can be shown by actual experiment 
that a difference of potential exists be- 
tween adjacent turns. This potential dif- 
ference creates an electrostatic field and 
energy is stored between the conductors. 

A condenser is a device which stores 
electrostatic capacity. It is evident there- 
fore that a condenser is formed, the plates 
of which are the adjacent conductor turns. 
The capacity is stored in the space between 
each turn of the coil and over all of the 
turns, therefore the capacity is distributed 
over the entire conductor. 

Referring to Fig. 1, it will be seen how 
distributed capacity is related to coils. In- 
creasing the length of the coil, increases the 
distributed capacity as it is seen that the 
number of condensers are increased. Since 
increasing the number of condensers in 
parallel increased the capacity, therefore 
we may consider all the parallel condensers 
as one large capacity shunted across the 
inductance, as indicated in Fig. 2. 

When capacity and inductance are linked, 
in a circuit we have an oscillatory circuit, 
and the period of vibration of such a sys- 
tem is directly proportional to the square 
root of the product of the inductance and 
capacity multiplied by a constant Ex- 
pressing the above in an algebraic form 
we have: 

n = , 4 ■ (l) 

Here n = period of vibration of the sys- 
tem. The wave length of the above cur- 
rent is, 

A = 59.6V£~c W 




Representing the Relation of Distributed 
Capacity in a Coil (Fig. 2) and the Voltage 
and Current Distribution in Inductance Coils 
(Fig. 3). 

where L and C are the inductance and ca- 
pacity. 

It is evident therefore that since the coil 



By SAMUEL COHEN 

has distributed capacity that the coil is an 
oscillatory circuit in itself, and it was found 
by actual experiment that when properly 
excited by a high frequency current, it will 
oscillate, the period of which depends upon 
the magnitude of the units of inductance 
and capacity. 

The true wave length of a circuit con- 
taining a large inductance and shunted with 
a capacity is not the same when calculated 
with formula (2) but the exact wave 
lengths will be as exprest in the follow- 
ing relation : 

a = 59.6 -s/L(C +C X ) < 3 > 

Where C is the capacity of the shunted 
condenser and to it we add the distributed 
capacity of the coil Cx. Solving for Cx 
we have : 

C«= A ~ LC ' (4 ) 

Calling the total capacity Ct equation (4) 
becomes : 

Cl= (59^Z (5)31 

It has also been found by actual experi- 
ment that whenever a large coil was ex- 
cited by radio frequency current it will 




Primary, str/fc/) ' 

K Smk/) 0.0 ooint 
--J^^S^w^ off 'point r> 



Fig. 5. Dead-end Elimination Switch for 
Loose Couplers Which Has Proven Very 
Effective in Reducing Distributed Capacity 
in the Windings. 



oscillate in its own period just the same 
as a coil shunted with a condenser and 
excited. The current and voltage relation 
of this coil is exactly the same as for a 
Hertz oscillator, where the current value 
is a maximum at its center and minimum 
at the ends, while the voltage is maximum 
at the ends and minimum at the center. 
Fig. 3 shows grafically this relation of the 
coil. 

The best means for determining the dis- 
tributed capacity is by actual measurement. 
The essential instruments necessary for this 
kind of work are calibrated inductance and 
capacity which may be obtained from a 
wave meter, a high frequency buzzer and 
an additional condenser. The instruments 
are connected as indicated in Fig. 4. The 
coil, whose distributed capacity is to be de- 
termined, is placed in a single loop of wire 
L, Fig. 4, which is excited by the buzzer, 
Placing the wave meter inductance L 2 near 
the excited circuit the condenser C 2 is 
turned for indicating resonance. When the 
point of resonance is obtained the period 
of vibration of both circuits are the same 



T = T. Substituting the observed values 
in the equation, 



Cd = 



(5) 




Arrangement of Apparatus for Measuring 
the Distributed Capacity in a Coil. A Buzzer 
Serves for Excitation of the Coil Under 
Measurement, While a Wave Meter Is Used 
to Ascertain the Wave Length of the Coil. 

Where L 2 = the inductance of wave meter 
coil in centimeters. 
C 2 = capacity of condenser at point 

of resonance in m.f. 
Li = inductance of coil, the distri- 
buted capacity of which 
to be found. 
It is advisable before starting to meas- 
ure the distributed capacity of a coil, to 
determine before-hand the magnitude of 
the figures so as to enable us to procure 
approximately the proper inductances and 
capacity in the wave meter circuit. It can 
either be found by judging it from expe- 
rience or else by actually calculating its 
value. An approximate formula has been 
derived by Drude for the calculation of the, 
distributed capacity as follows : 

Cd=2K T - 5— (6) 



10+4 



+ 3- 



Where "h" and "r" are the length and 
radius of the coil respectively. The con- 
stant K is obtained from the following 
table, which is for air core coils. 
h/zr K h/2r K 

6 1.81 0.8 1.10 

5 1.64 0.6 1.07 

4 1.74 0.4 .94 

3 1.37 0.2 .69 

2 1.26 0.1 .49 

1 1.12 0.05 .28 

Having determined the distributed ca- 
pacity of a coil, what are we going to do 
with this? The only thing that we are 
trying to do with it is to decrease its 
value in the coil as much as possible. There 
are several methods of decreasing the so- 
called dead-end effects in radio coils. The 









I 


III 


m 


m 


ill 


Hg. 6 


© 



Radio Inductances Have Their Distributed 
Capacity Reduced by Winding the Coils in 
Groups, With a Space Between. 

best and most practical way is to discon- 
nect the portion of the winding which is 
not in use and this is what may be ac- 
complished by employing a special switch 
arrangement on the coil. A highly ingen- 
ious switch which serves the purpose very 
nicely was described in the "Question Box" 

(Continued on page 65) 



34 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



A Study of the Law of Response of the 
Silicon Detector 



A "WIRELESS" AUTO RADIATOR 
EMBLEM FOR AUTOS. 

The base of this nifty and appropriate 
auto emblem is made from an irregular 
shaped piece of wood, l A inch thick and 
about 8 inches long, by 3 l / 2 inches wide at 
the broadest end. The rocky effect is ob- 




Something New in a "Wireless" Radiator 
Emblem for Radio Enthusiasts Who Own 
a Car. By Pushing a Button on the Dash, 
Sparks Are Caused to Jump a Small Gap 
Inside the Miniature House. 



tained by mixing thin glue and plaster of 
paris and water to a thick paste and mould- 
ing it on the base, which has several quar- 
ter inch holes bored through it, to give the 
plaster a secure foundation. Papier-mache 
is very good for the purpose or the base 
can very well be moulded from white metal 
or lead and afterward painted. The radio 
masts and connections will then, of course, 
have to be especially well insulated. The 
coil and condenser must be kept close to 
the spark gap. 

One of the masts is 8 inches long and 
the other 4 inches long, made of 3/16 inch 
brass or steel. The longer one is sunk 
into the plaster about two inches and the 
shorter one about 1 inch. The spreaders, 
% by 2 l / 2 inches, are equally divided for 
the four wires which are of No. 24 bare 
copper. The lead in rattail is soldered to 
the middle of the aerial. The insulators 
are tiny drops of black sealing wax mould- 
ed in ball fashion about the wire. 

Ropes of fine fish line and guys of silk 
cord are put on, also a station constructed 
of cardboard is placed at the base of the 




Circuits of Miniature Radio System Used as 
Radiator Decoration for Autos. Be Sure to 
Show Your Credentials to the Village "Con- 
stabile," or By Heck, He May Take You for 
a "Spy," with a Consarned, New-fangled 
"Wireless." Yessiree. 

taller pole. The whole, except the aerial, 
is given two coats of enamel, the poles 
being white and the ground and rocks of 



THE special form of silicon detector 
receiver designed by E. Merritt for 
use with short electric waves, and 
reported upon at the meeting of the Physi- 
cal Society, February 27, 1915, showed cer- 
tain peculiarities which made desirable a 
further study of the device. The investi- 
gation described in the following paper by 
Louise S. McDowell and Frances G. Wick 
in the Physical Review, includes, first, a 
study of the receiving device and the condi- 
tions under which it can be used to best 
advantage, and, secondly, a study of the 
law of response of the silicon detector with 
a variation in the energy of the incident 
wave produced by the rotation of a screen 
of parallel wires. 

The oscillator, receiver and screen were 
arranged as shown in diagrarri. The oscil- 
lator S consisted of a small spark gap in 
kerosene, extended by two straight alumi- 
num wires WW, to a length of 51 cm., and 
connected thru water resistances, HH, to 
the secondary of a small automobile induc- 
tion coil, K, using about 6 volts. The 
water resistances introduced served to 
damp any oscillations from the coil which 
might have produced disturbances. 

The receiver consisted of a silicon detec- 
tor, D, in series with a paper telephone con- 
denser, C, of 1 mfd. capacity, and with a 
loop of wire, NR. The connections to this 
loop were made by mercury cups, MM. A 
sensitive galvanometer, Gal., Leeds & North- 
rup type H, was shunted around the con- 
denser. An aluminum rod, OP, acting as 
a resonator, was supported parallel and 
close to the outer wire of the loop. The 
length of the resonator was 44.5 cm., giv- 
ing the maximum response to the wave- 
length used, about 100 cm. 

Between the receiver and the oscillator 
and parallel to them was placed a screen, 
EF, which could be rotated thru known 
angles. It consisted of iron wires stretched 
parallel to each other about 3 cm. apart, 
upon a wooden frame 2 metres square. An 
additional fixt screen of tin and wire net- 
ting, YAB, 3 metres high and 4 metres 
broad, completely divided the room, except 
for an opening, AB, left in the center. The 
rotating screen was placed close to this 
opening, on the side toward the receiver, 
at distances varying from 5 cm. to 10 cm. 
for different sets of observations. 

Merritt, in his experiments with the re- 
ceiving device, had noted that when the 
screen was placed with its wires parallel to 
the oscillator, the position which should 
allow no transmission, there was still con- 
siderable effect upon the receiver, amount- 



green and gray respectively. The copper 
wires are lacquered after being polished. 
Two heavily insulated wires (secondary 
cable) are then run up thru the hood 
of the car from a spark coil and condenser, 
which are operated from a push button on 
the dash or wheel, the same as a horn is 
controlled. These wires are connected to 
a brass wire spark gap of about V\ inch, 
which has been previously moulded into 
the plaster and which the station building 
conceals. If an ordinary ignition coil is 
used, then a suitable condenser may be 
formed of about four 4x5 glass plates, 
coated on both sides with tinfoil leaves 1 
inch smaller all around. Connect as shown 
in cut. 

The rest is easily imagined. The sur- 
prise at the sight of the tiny flashing win- 
dows and the crash of the spark gap is 
bound to command attention from anyone. 
Try it boys and see if I'm right. 

Contributed by LES GLEIM. 



ing at the least to about one-fifth of the 
maximum effect, when the wires were verti- 
cal (the position for complete transmis- 
sion). The cause of this residual effect 
was unknown. He observed, also, that 
as the wire screen was rotated thru 360 
deg. there was a variation in the response 
in the different quadrants. Early in the 
present experimental work it was found 
that when the resonator OP, Fig. 1, was 
removed the receiving apparatus still re- 
sponded, although weakly, to waves from 
the oscillator. The receiver was then 
studied in order to discover what changes 
in the design would affect the response 
without the resonator, and how it could be 
reduced to the minimum consistent with 
sensitiveness of the receiver as a whole; 
also to discover the cause of the residual 
effect when the screen was in the position 
of no transmission. Experiments were 
made with the plane of the receiver both 
vertical and horizontal. 

Receiver in the Vertical Plane. 

The receiver was mounted on a T-shaped 
board and suspended by rubber bands from 
a cross-bar rigidly fastened to the ceiling. 
To prevent reflections, practically all re- 
movable metal was taken from the room 
and from the adjoining rooms. To re- 
duce any difficulties arising from reflections 
from surrounding metal objects, the room 
was completely divided cross-wise by the 
fixt screen described above, and the ro- 
tating screen was placed in front of the 




Miniature Radio Transmitter and Receptor, 
With Screen E-F Interposed Between Them 
and By Which Means the Law of Response 
of the Silicon Detector Was Studied. 



opening. The residual effect was then 
found to be considerably reduced. 

The screen was then rotated thru 
360 deg. and readings were taken every 
20 deg. both with and without the resona- 
tor. From the observations made three 
curves were plotted, in which the ordinates 
were galvanometer deflections and the ab- 
scissae the angles between the parallel 
wires of the rotating screen and the ver- 
tical. 

The curve obtained with the resonator 
had a maximum at 15 deg. and a minimum 
at 100 deg., whereas without the resonator 
four maxima at the 45 deg. positions were 
obtained. Curves taken out of doors were 
similar in form to those obtained indoors. 

To determine the effect of the design of 
the receiver upon the response without the 
resonator, series of observations were made 
with loops of various shapes and sizes. To 
get the effect upon the loop alone, the re- 
ceiver was screened by a tin cylinder up 
to the mercury cups MM. To test the re- 
sponse to the vertical and horizontal com- 
(Continued on page 74) 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



35 



AUXILIARY RELAY BREAK FOR 
COHERERS. 

While the coherer is used but little in 
modern radio receiving sets, still, it is 
quite invaluable in making wireless demon- 
strations at lectures and for other radio 
control experiments. 

One of the principal troubles develop- 
ing in the operation of the tilings coherer 
is that, it is so extremely sensitive to every 



Coflerer 



,1 R Pin 




SYbof 



An Auxiliary Contact Fitted on the Relay 
of a Coherer Set Serves to Cut Off Local 
Oscillations from the Coherer. 

little spark discharge in its immediate 
neighborhood and it is invariably found 
that the sparking at the relay contacts or 
at the decoherer contacts, will set up oscil- 
lations which will pass along the connect- 
ing wires of the coherer circuit and tend 
to act on it the same as an incoming wire- 
less wave. 

This trouble is overcome to a great ex- 
tent by shunting the relay and decoherer 
contacts with high resistances, of the or- 
der of 2,000 to 4,000 ohms (wound non- 
inductively), and also by the insertion of 
choke coils in the lead wires between the 
coherer and main relay. 

However, there is another scheme, not 
so well-known, perhaps, and which works 
very favorably indeed with the above pur- 
pose in mind. This consists of an auxil- 
iary contact on the relay or decoherer, 
which so functions that the coherer cir- 
cuit is opened as the relay or decoherer 
circuit "breaks," and thus the possibility 
of locally produced oscillations affecting 
the coherer are greatly reduced. Choke 
coils are not necessary with such an ar- 
rangement, but if used as an extra pre- 
caution, they can be made up of a fine, 
soft iron wire core 4 inches long by 54 
inch diameter, wound with four layers of 
No. 26 gage insulated magnet wire, con- 
nected as shown in diagram. 

USING "AUTO" SPARK COIL FOR 
RADIO. 

This is a handy "hook-up" for those 
using an auotmobile ignition coil with three 
terminals, one of them being common to 
both primary and secondary. By using this 
connection scheme with an ordinary 



DPDTSn 



}\ i 7 



Condenser 



To rec 
set 



m- 



Auto coil 




How to Hook Up an Auto Ignition Coil for 
Wireless Transmitting. 

D.P.D.T. knife switch, it becomes impos- 
sible to press the key accidently and knock 
the detector out of adjustment when re- 
ceiving. 

Be sure to connect that blade of the 
switch which connects with the common 



terminal of the coil to the ground wires; 
otherwise a severe shock will be received 
if the uninsulated part of the key is touched 
while sending. 
Contributed by 

GEO. F. HARRINGTON. 



SINGLE VS. MULTI-LAYER RADIO 
INDUCTANCES. 

In the protection of radio frequency ap- 
paratus one of the most important points 
is the insertion of choke coils to localize 
properly the radio-frequency energy. I do 
not think it is as fully appreciated as it 
should be that multiple-layer coils are al- 
most useless for this purpose, says Benja- 
min Liebowitz in the February, 1917, Pro- 
ceedings of the Institute of Radio Engi- 
neers. Because of their large effective dis- 
tributed capacity, radio frequency currents 
are propagated with great ease thru such 
coils, and often with disastrous results. 
Thus, in one instance, I employed as a 
choke coil an inductance of about 600 turns 
of number 18 B. and S. wire wound in 30 
turns per layer, and burned out a generator 
in consequence. I replaced this coil by six 
single-layer spirals, about twenty-four 
inches (61 cm.) in inside diameter, each 
spiral having eighty turns of copper rib- 
bon 0.50 by 0.01 inch (1.27 by 0.025 cm.) in 
section, insulated by paper ribbon of the 
same section. The six spirals in series had 
somewhat less inductance than the multiple- 
layer coil first used, but to currents less 
than 100,000 cycles in frequency they were 
an almost perfect barrier. It cannot be 
too strongly emphasized that distributed ca- 
pacity is just as undesirable in choke-coils 
as it is in radio frequency circuits. 

A "COIN" RADIO DETECTOR. 

Wireless Bugs, try this on your detec- 
tor. Procure a ten cent piece; if not handy 
try five cent piece. Put either of the coins 
in the detector cup and proceed to adjust 
for a "sensitive spot, as you would with 
galena. If your are not satisfied with the 
results, try another coin. 

The writer has experimented successfully 
with both coins, but prefers the DIME as 
it does finer work than the NICKEL. 

(Evidently quality counts, for dimes are 
said to be more expensive than nickels ! ! 
Next ! ! !— Editor.) 

Contributed by WILLIAM MILLER. 

A SINGING SPARK INTERRUPTER. 

Many amateurs, like that King of long 
ago, have muttered "My kingdom for a real 
musical spark." as they struggled with the 
stuttering, stammering interrupters usually 
attached to small spark coils. The mere 
note stamps them as beginners and the big 
fellows don't want to bother listening to 
the low-pitched code emitted from such 
stations. 

But a great obstacle lies in their path in 
obtaining the oft wisht for, high pitched 
note. Beside the mechanical difficulties 
there remains the fact that when the in- 
terrupter is speeded up, the range is short- 
ened, due to the fact that the core of the 
coil does not become thoroly saturated with 
magnetism in the short time that the circuit 
is closed, with the result that the induced 
currents in the secondary circuit are not as 
powerful as they should be. 

The interrupter described herewith dots 
away with mechanical difficulties in a sim- 
ple and effective manner, the only cure for 
the above mentioned condition being to in- 
crease the voltage of the supply current. 
By doubling the voltage very good results 
will be obtained with the following device. 

The regular spring interrupter is removed 
from the spark coil and mounted on a con- 
veniently sized base. Two uprights are cut 
from T 4 inch square brass rod 4 inches 
long. Both ends of these rods are drilled 
and tapt for an 8-32 screw. One-half inch 



A DRUM TYPE ANTENNA 
SWITCH. 

Herewith is a diagram of an aerial 
switch for use in small stations. It is of 
the rotary drum type as seen. By refer- 
ring to Fig. 1, it will be noted that the 



to rec set 




A Rotary Control, Drum Type Antenna 
Switch Is Easily Made on the Above Plan. 

parts are numbered as follows: 1 — binding 
posts; 2 — electrose knob; 3 — wooden cylin- 
der; 4 — brass segments on cylinder; 5 — ■ 
brass contact brushes ; 6 — box (wood or 
rubber 4x3x2 inches). The best job is 
made by using a hard rubber cylinder, sup- 
ported on two small pins as shown at Fig. 
2. The current for A and G is then car- 
ried thru the two shafts to segments 4. 
Contributed by HAROLD DAVIE. 

from one end of each rod a Y% inch hole 
is drilled to pass the two small round rods 
H H, as shown in the illustration. The 
square rods are mounted on the base as 
shown. The round rods put into place while 
screws, S S, clamp the latter in position. 

The end of the interrupter spring is cov- 
ered with small strips of mica held in place 
by thick shellac. This mica is to insulate 
the spring from the length of German Sil- 
ver wire which passes under the spring and 
is wrapt around the two small brass rods as 
illustrated. The wire used may be No. 26 
or No. 28 bare German Silver. The wiring 
under the base is shown in dotted lines. 

To adjust, turn the vibrator screw all the 
way out to tighten the German Silver wire 
until it raises the spring slightly. Close 
the key and slowly turn the vibrator screw 
down till the desired note is obtained. 

The operation deoends upon the expan- 
sion and contraction of the wire which 
takes place at an unbelievably high rate of 
speed. The note obtained is very musical 
and in connection with the higher voltage 
in use, will increase the range of the set. 




We All Desire to Have a High Note Spark. 
Here's How — A Piece of German Silver Wire 
Serves to Hold Back the Free End of the 
Vibrator Spring, Reducing Its Swing and 
Raising the Freguency. 

It is advisable to renew the wire occa- 
sionally, as the heating crystallizes the mole- 
cules and after a certain length of time will 
refuse to respond. 
Contributed by THOS. W. BENSON. 



3 6 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



M C2N5TRV1QT2R 

mnr- ir~ h — k — it — \r~ir ir . 'jr^r^r~-ir---nr-~ir-ni — irrn 




An Electrical Paradox or Selective Lamp Controller 



THE average person is always in- 
terested in a puzzle. When that 
puzzle is electrical, it is certain 
to appeal to the amateur experi- 
menter. Can any of you think 
of an arrangement by means of which a 
single pole, single throw, knife switch may 
be made to operate three different lamps 
individually, during three successive inter- 



BY ALBERT H. BEILER 

A wooden cylinder, G, is fixt on A, which 
has brass segments fastened along its peri- 
fery as shown at E. It will be Seen that E 
touches one of the brass strips I. This 
closes- a circuit and lights a lamp. If some 
means could now be employed to move the 
wooden cylinder Yz of a revolution, another 
segment seen slightly under the middle 
brass strip would touch the strip, while the 



■19 7 

Rear*V/ew of Arm 



ig.3 
Front V/etv 




Fig 1 
Reor V/ew 



Perspective View of Selective Lamp Control 
Gear Wheels and Other Odd Parts. At the 
Unit with Gear Attachment fo 

vals that the circuit is closed? For exam- 
ple, if the switch is closed once, light No. 
1 will light and remain lit until the switch 
is opened again. It will then go out. If 
the switch is again closed, light No. 2 
ONLY will light and remain lit until the 
circuit is again opened. Similarly with light 
No. 3. 

To secure the result described, an ar- 
rangement is employed somewhat similar 
to that used on the automatic block signal- 
ing systems of single-track electric rail- 
roads, and elsewhere. A commutator is 
made to move from one contact segment to 
another every time an electro-magnet 
draws its armature down (or up). 

Referring to Figs. 1 and 3, when the cir- 
cuit is closed, the magnets attract the arV 
mature, pulling it down. The hook C 
catches over a tooth of the ratchet wheel 
R. By noting the direction of pitch of the 
teeth, it will be seen that the movement of 
the hook will not cause the ratchet to move. 
The ratchet is rigidly attached to a, shaft 
B, on which a gear wheel K is also firmly 
fastened (Fig. 1). This cog meshes with 
\ smaller one, J, which is tight on shaft A. 



ler Built from a Telegraph Sounder, a Few 
Left Is Shown the Brushes and Commutator 
■ Rotating the Segment Drum. 

first segment would have moved away from 
the end strip. Another third of a revolu- 
tion would cause the foremost segment to 
touch the foremost I and close another cir- 
cuit, while the other two circuits would re- 
main open. When the switch is closed, 
the cylinder with the brass segments, called 
the commutator, will not move, but the hook 
will engage a tooth of the ratchet. Simul- 
taneously a lamp will light. 
When the switch is now opened, 
the lamp will go out and the 
same instant the retractile 
spring T will pull the armature 
up again, since the magnets 
have lost their power of attrac- 
tion. Hook C will pull the 
ratchet up a distance equal to 
its (the hook's) travel. This 
distance is such that the ratchet 



ratchet makes l/12th of a turn, K will also 
turn l/12th of a revolution. Thus the 
third of a revolution movement, which is 
necessary to bring each segment under 1 its 
respective contact, is accomplished. 

It is possible that the reader who has fol- 
lowed this explanation carefully will ask 
why the movement of the ratchet should be 
accomplished by the retractile spring T 
when the magnet exerts a greater force. 
In other words, why should not the seg- 
ments change on the down stroke of -the 
armature instead of on the up stroke? The 
answer is this : Suppose the commutator 
turned if a circuit was closed instead of 
when it was opened, then, for an instant 
the lamp would light which had just pre- 
viously been lit. It is true that almost im- 
mediately it would go out and the required 
lamp would light but the result would very 
obviously be unsatisfactory. The time taken 
for the cylinder to commutate would be the 
time required for the magnets to pull the ar- 
mature down. As this does not occur in- 
stantaneously, the above described result 
would occur. Another objection to having 
the commutator rotate on the down stroke 
of the armature is that a segment and a 
brass strip, each carrying current, would be 
separated from each other by the movement 
of the commutator and create a spark 
which would soon pit the segments and 
brass contacts and thus interfere with the 
satisfactory operation of the device. With 
the device arranged as just described the 
commutator moves an instant AFTER the 
circuit has been opened, thus preventing any 
arc from forming. 

The wiring diagram is shown in Figure 
8. B B B are the strips I of Figure 1. 
C represents the commutator segments. M 
is the electro-magnet. R is the rheostat, 
made of salt water with carbon electrodes, 
or sulfuric acid, and carbon or lead elec-' 
trodes. Two 100 watt lamps in parallel may 
be connected in series with the magnet in- 
stead of the rheostat. The magnets must 
receive from V/2 to 2 amperes, since they 
have quite a pull to make. The smaller 
circles B show where the wires from the 
device are connected to the .binding posts 
seen in Fig. 1. 

Anyone sufficiently interested may make 
one of these contrivances by following the 
diagrams and instructions which follow. 




will ha vp rnmnlptpd 1 /12th nf a Photo of Selective Lamp Switch or Controller as Built 
will have completed i/iztn 01 a thg Authorj Together with Three Lamps to Be Con- 
revolution when the armature trolled and Main Circuit Switch. 

shaft F strikes its stop screw 
N. It must here be stated that th.e ratchet 
has 12 teeth, gear K, 48 teeth, while 
gear J has 12 teeth ; the ratio between 
the two latter being 4 to 1. When the 



Secure an old telegraph sounder of the 
sort that is generally sold to amateurs for 
practising telegraphy. Unscrew the parts 
from the base and mount the frame, mag- 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



37 



nets and armature on 4 columns consisting 
of six l /% inch fibre washers, the whole being 
mounted upon a suitable baseboard of 9 
inches by 6 inches oak (Fig. 3). The piece 
L is of Yi inch brass Y\ inch long and is 
threaded at both ends so as to receive the 
adjusting screw of spring T at one end 
and a screw that holds L to the base at the 
other end. One-and-one-half inch stove- 
bolts, Q, hold the frame of the sounder to 
the base. The machine screws to hold the 
magnets must be 2 inches long in order to 
go thru the base, the washers, the yoke of 
the magnets and finally screw into the mag- 
nets themselves. 

Then shape a hook of % or 3/32 inch 
stock, as shown in Fig. 2. A fret saw may 
be used to cut it out with, but any one at 
all handy with a file can shape the hook 
quite as well. 

Now remove the armature of the sounder 
by pressing the uprights outwards. Drill 
and tap a hole for an 8/32 screw Y\ inch 
from the end of the armature shaft (Fig. 
7). Slip an 8/32 machine screw into the 
upper hole of the hook and screw it into 
the armature, so that the hook swings easily 
but has very little play. Lock the bolt on 
the other side of the armature by a nut M. 
The armature now looks as in Fig. 7. 

The commutator is made from a small 
wooden cylinder having a hole bored thru 
it longitudinally. Brass segments are 
screwed round it, in a manner to be de- 
scribed. The author found considerable 
difficulty in securing a cylinder of suitable 
size, but he finally used one of the small 
wooden rollers on which the paper for add- 
ing machines is wound. Such a cylinder is 
$Y% inches long, % inch in diameter and has 
a 7/16 inch hole thru it, and will answer 
very well for the purpose. 

Cut a piece of 1/64 inch brass as shown in 
Fig. 4 and drill small holes near the corners 
as indicated. The brass is attached to the 
cylinder by small '4 inch brass screws. Screw 
one segment of brass down on the cylin- 
der near one end, then bend the brass 
around the cylinder and screw the second 
segment on. A reference to E and G of 
Fig. 1 will serve to make this clear. Be- 
fore screwing the last segment down, drill 
a small hole diametrically thru the roller 
to meet the central hole, and pass a thin 
wire thru it, so that the wire is underneath 
the last segment. The other end of the 
wire should come out thru the last hole in 
the cylinder. It will now be evident that 
there is an electrical connection from the 
protruding wire to every commutator seg- 
ment. 

The shaft for the commutator is made of 




Wiring Scheme for the "Electrical Paradox" 
Which Enables the Manipulator to Success- 
sively and Individually Light and Extin- 
guish Any One of Three Lamps, by Simply 
Operating the Main Switch Three Times. 

7/16 inch steel or brass, inches long. 
The details for it are shown at A (Fig. 
5). Force the shaft into the hole in the 
cylinder so that it projects the same dis- 
tance from either end. While putting the 




.11 



19 dr/tt 



Ratchet hook 
fig. 2 



-D- 



® 



Fig. 6 



shaft in, the wire that comes thru the hole 
will be caught between the shaft and the in- 
side wall of the cylinder, so that an electri- 
cal circuit is established from the shaft to 
all the segments of the commutator. The 
brushes I (Fig. 1) that bear against the 
segments are of J/4 inch wide spring brass. 
Three of these are needed, 3 inches long. 
They are supported on the two oak blocks 
H H, 3 3 /s inches long, by V/ 2 inches wide 
and y 2 inch thick. One of the oak blocks 
must have three small 
holes thru it so that 
the holes are vertical 
as the blocks stand on 
end. The outer two 
holes are 9/16 inch 
from the end, and the 
inner one is in the cen- 
ter. These holes are 
for the wires which 
connect the brushes to 
the binding posts. 
Drill y» inch holes in 
the brass strips as 
shown (Fig. 1) but do 
not fasten them to the 
oak blocks until later. 

Procure a ratchet 
wheel R (Fig. 3) V/&' 
inches in diameter, and 
l /$ inch thick, also two 
cog wheels, J and K 
(Fig. 1), K being 1^4 
inches long and having 
48 teeth, and J having 
12 teeth. The larger 
cog and the ratchet 
should each have a Y\ 
inch hole thru their 
centers, the smaller 
cog a 3/16 inch hole. 

Then turn a shaft B, 
the details of which 
are given in Figure 5. 
The end bearings for 
the two shafts are 
made of 3/32 inch or Y& inch wrought iron. 
They may be shaped as shown at X (Fig. 
3) or V (Fig. 1). Bearing X has a Vs inch 
hole drilled 13/16 inch up, and Y has a Ys 
inch hole drilled 1 1/16 inches up from the 
bottom. The center bearing D (Fig. 1) 
must be wider than the other two since it 
supports both shafts. The details for its 
construction are shown in Fig. 6. The 
holes should be laid out very carefully and 
accurately, as upon them depends the prop- 
er meshing of the two cogs, and conse- 
quently the smooth operation of the con- 
trivance. 

The uprights U and Y are made of Y% 
inch brass or steel. They are threaded at 
the lower end so as to be held down to the 
base by nuts. U should be about 2Y inches 
high and Y, 2 inches. Three-eighths inch 
from the top of Y, drill and tap a hole 
diametrically thru it, to receive an 8/32 
spring adjusting screw. On U solder a 
cross-piece which has an adjusting screw 
and lock nut N in it. Place U so that 
when it is screwed down, N will touch the 
center of the armature shaft. Y is direct- 
ly in front of the ratchet, but far enough 
away so as not to interfere with the rat- 
chet's operation. 

The parts are now ready for assembling. 
First put the armature shaft back into its 
supports. Then place the small bearing X 
in such a position that when the ratchet is 
put on the shaft and the shaft into the 
bearing the hook will engage a tooth of the 
ratchet. (Be careful to have the direction 
of pitch of the ratchet just as shown in Fig. 
3 and not the reverse way.) When the po- 
sition of bearing and of the ratchet have 
been determined, solder the latter to shaft 
B in the required position, and also solder 
cog K to B, about 1/16 inch from the end 
of the shoulder. Bearing X may now be 
screwed down. 



Pass the long shoulder of shaft A, i.e., the 
left end (Fig. 5), thru the upper hole of 
bearing D. Then force the small cog J on 
to this long shoulder far enough so that 
there is very little play, but not so far as 
to cause the cog to bind on the bearing. 
Now place the cog wheel end of shaft B 
into the lower hole of D, and if the work 
has been done correctly, the cogs will mesh 
with each other. Then slip bearing Y on 
to the other end of the commutator shaft. 



Commutator shaft 
s" 



IT 



-3- 



Ratchet shaft 
Fig 5 

f 4c drill 



holes drilled '/ 
from each side 



flow to cut commutator segments 
Fig 4 _ 



Detail Working Drawings of Parts Necessary in Constructing the 
"Electrical Paradox." 

After a little experimenting to place the 
bearings in such a position as to make the 
parts turn with as little friction as possible, 
screw bearing D and Y down (after shaft 
B is in position of course). Before screw- 
ing Y down, drill a small hole thru the 
base directly beneath it ar J pass a thin wire 
thru this hole so that the bearing will press 
on the wire. Connect the other end of the 
wire underneath the base to a binding post. 
It will now be noticed that contact is es- 
tablished from the binding post to bearing 
Y, from Y to the shaft A, and from there 
to the commutator segments E E E. 

Place the oak blocks parallel to the com- 
mutator, at equal distances on either side 
of it and 3 inches apart. Drill 3 small holes 
thru the base at places to correspond with 
the 3 holes in one of the blocks. Then 
fasten the blocks down to the base with 
screws. (It must be clearly understood 
that the screws DO NOT go thru these 
holes, but thru other holes which may be 
bored for the purpose.) Pass a wire 
thru each of the holes in the base 
and thru the block, so that they project 
from the top. Now screw the brushes down 
on the blocks (this time the screws go 
thru the holes in the block). Connect the 
three wires from the under side of the 
base to three binding posts. Contact is 
now established from each binding post to 
each brush and to that commutator segment 
which happens to be touching that brush 
at the moment. Connect one of the wires 
from the magnet to a binding post and the 
other wire splices on to the wire coming 
from bearing Y. (Refer to Fig. 8.) Put 
a light brass spring S thru the hole in C 
and hook it over the spring adjusting screw 
in Y, so that it can be adjusted to any ten- 
sion. The spring T is of fairlv heavy steel, 
since it is its tension that really drives the 
(Continued on page 74) 



38 



THE ELECTRICAL EXPERIMENTER 

An Illuminated Stage Sulky 



May, 1917 



SEVERAL years ago the author of this 
article had occasion to work up an illu- 
mination scheme for a small two-wheel 
sulky and harness to be used in a stage act. 

Owing to the fact that the horse in this 
act performed many difficult tricks, with 
the result that the sulky was pitched at 




Appearance of Electrically Illuminated Stage 
Sulky and Harness. 



many different angles and also for other 
reasons, storage batteries were not allow- 
able. The scheme shown diagrammatically 
herewith was successfully developed and 
applied and the results were very satisfac- 
tory, particularly when the display of the 
illuminated harness and vehicle was shown 
on a darkened stage before black velvet 
drop curtains. 

Briefly considered, the battery comprised 
36 dry cells of standard size, connected in 
series-parallel to give 18 volts. The feed 
wires in the battery box, which was painted 
white to correspond with the trimmings of 
the balance of the vehicle and placed be- 
neath the seat, were led to the various cir- 
cuits about the sulky body and wheels and 
also to the harness. 

The harness display consisted of a num- 
ber of 16 volt battery lamps connected on 
parallel, the terminal wires ending" in a 
separable connector, so that it could be in- 
stantly detached from the vehicle when de- 
sired. 

A small switch placed in one of the main 
battery leads and arranged on the side of 
the seat frame, enabled the driver to switch 
on the lights at the critical moment when 
the stage had been properly darkened. 



By HARRY S. TOWNSEND 

that it would be unnoticeable to those in 
the audience. The rear (facing the au- 
dience j side of the disk was painted white, 
the same as the wheels. 

Three sixteen volt lamps were placed 
on every other spoke and several lamps 
were also secured to the fiber disk on its 
rear face so as to form a circle in con- 
junction with the inner lamps of the spoke 
strips. Lamps were also spaced in be- 
tween, around the rims of the wheels, as 
seen in the illustration. 

A detail of the round woven-wire 
brushes and brush holders is given in the 
illustration. The wiring was done with 
No. 14 rubber covered 1 conductor for the 
main battery leads, and with No. 16 R.C. 
fixture wire for the independent circuits. 

This arrangement, as will be observed 
by the reader, does away entirely with 
the nuisance of a trailing stage cable, 
which many electrical acts are burdened 
with. Altho not shown here, the various 
circuits were specially arranged so as to 
permit grouping into series — parallel on 
110 volt lighting circuits when the occasion 
demanded. This required 4 contact rings 
and 4 brushes on each wheel, also a spe- 
cial disposition of the harness and vehicle 
circuits. 




Rear View of Sulky Showing the Battery Box and Control 
Switch Within Easy Reach of the Driver. 



One of the most difficult problems was 
to convey the current properly to the ro- 
tating lamp strips secured to the spokes 
of the wheels. This was accomplisht by 
means of two brushes and a two ring 
commutator fitted to the side of each 
wheel. 

The commutator disk was made of fiber 
and not more than 9 inches in diameter so 



HOW TO MAKE CARDBOARD 
CYLINDERS. 

Those radio-bugs who construct their 
own loose couplers and loading' inductances 
are generally hampered by not being able 
to construct suitable forms on which to 
wind the wire. The following method I 
have found satisfactory and it takes but a 
few minutes to construct a serviceable 
tube of any desired size and thickness. 

Having the plugs of the desired diameter 
ready, cut off a strip of thin cardboard slight-, 
ly greater in width than the required length 
of the tube to be made. Now lay the card- 
board on the table and proceed to roll the 
plugs. After making one revolution spread 
glue liberally over the remaining part and 
finish rolling it up. If the tube is not as 
thick as desired, another strip of cardboard 
can be wound over the first. It is well not 
to have the tube fit too tightly over plugs, 
or trouble will be exper- 
ienced w i t h shrinkage 
during further treatment. 
The tube is now wound 
with tape or cord and 
placed in a moderately 
hot oven for fifteen min- 
utes or more. 

After removing from 
oven, trim edges carefully 
and while still hot give it 
a thoro coating of orange 
shellac inside and out. 
While the shellac is still 
fresh, take your blow 
torch and with a sweeping 
movement burn the shel- 
lac into the tube and re- 
peat the process. It is 
well to make sure you are 
using pure shellac, not 
cheap glue, as some so- 
called shellacs are (I 
make my own shellac out 
of orange shellac flakes 
dissolved in grain alcohol). If you do not 
have a blow torch handy, a good heating in 
the oven will do altho it requires more time. 

The appearance of the tube is greatly im- 
proved by blackenine the ends. A thin 
paste made up of black aniline dye, dis- 
solved in white shellac, gives a glossy black. 
A black looking luster can be made of lamp- 
black mixed with orange shellac. The for- 



n.er is preferable, having better insulating 
qualities than the latter. 

A little experience in tube making will 
soon make you proficient in the art. At a 



Sockets 



Hole for hub, *«st 
'enfhmoch. ■ ' 




Details of Sulky Wheels and the Metal Con- 
tact Rings and Brushes Whereby Current Is 
Conducted to the Lights on the Spokes. 

small cost moisture proof tubes can be made 
quickly, saving valuable time in waiting. 

Contributed by 

CHARLES M. FITZGERALD. 



HOW TO FROST LAMPS QUICKLY. 

Take the bulb and smear over thoroly 
with a good library paste ; after which dip 
into a cup of sugar or salt crystals. Then 
let stand for awhile. Do not use glue for 
an adhesive as this has a tendency to dis- 
solve the salt or sugar. 

Contributed by JOHN T. DWYER. 

TO USE OLD BATTERY ZINCS. 

When the lower half of a battery zinc is 
eaten away by the action of the electrolyte, 
the remaining portion can be utilized by sus- 
pending it from a wire, so that the zinc is 
covered by the battery solution. 

A very good electrical connection should 
be made between the wire and the zinc and 
the joint covered with melted paraffin. This 



© 




_j2 



Hmiiit — iiiiiii"- 
Humii — liimiH 

-O- 36 dry ce//s in ser/es \po/v//e/ 




-O 

-o- 
-o- 



tlorness Ig'ts 

1 



Wiring Diagram for 36 Dry Cell Battery and 
Various Lamp Circuits on the Sulky and 
Harness. 



last precaution is necessary as otherwise 
corrosion would soon occur from the action 
of the salammoniac or other chemical. The 
wire may be held at the top of the jar by 
twisting around a small piece of wood. 
Contributed by K. M. COGGESHALL. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



39 



UNIQUE INDICATOR SYSTEM 
WHICH ANNOUNCES THE 
ICEMAN AND GROCER. 

A "step-saver" — that's just what this de- 
vice is, for, when constructed, it will save 
Mother or the housekeeper many a fruit- 



Fig I 



fig 2 



® 



Spring 




6/oss mndoiv 



'II 








'oai 

t 


= (III 




Vie/oii 



Cor Don >VJ 




dufomofic it re/eose 



The Women Folks Need Not Run to the 
Door for the Iceman and Grocer, When This 
Apparatus Is Installed. The Tradesman 
Turns the Switch Lever to the Proper 
Number; the Kitchen Indicator Shows Who 
Is Calling and the Cook Pushes the Button 
Marked "Coming" or That Labeled "Nothing 
To-day." 

less trip to the door in response to the 
ever-ringing bell, because it enables her to 
know who is calling, whether the milkman, 
baker, etc., and signal to them if their goods 
are needed or not — all without requiring any 
more effort on her part than merely pushing 
a button. 

The first thing required is a wooden 
frame or case, similar to that shown in 
Figs. 1 and 2. Inside of the same are ar- 
ranged the indicator magnets and also the 
magnets controlling the automatic switch 
release (A in Fig. 1). This latter may be 
simply the armature and tapper rod of an 
ordinary battery bell, bent as illustrated in 
order to allow the extremity to act as a 
check pawl on the four-cam wheel, which 
is centered on a shaft manipulated by the 
switch handle. It will be seen that this 
prevents the switch, when once set at the 
point desired, from falling back to its 
original position after pressure has been 
removed. The cam wheel, if not procurable 
from old clock works, can be easily turned 
out of wood by a jig saw or of brass in a 
lathe. By the same methods any other 
parts of this device may be constructed 
when lack of simpler means prevents 
otherwise. The carbon strip (another form 
of resistance may be used if this is not 
handy) can be cut out from the carbon 
electrode of an old battery cell and should 
be placed on the inside of the box directly 
over the groove, by means of which the 
switch makes contact with it. The parti- 
tion B, in Fig. 1, should have two holes for 
the insertion of the core ends of the electro- 
magnets M' and M", which, on being act- 
uated, raise up one or the other gravity in- 
dicators, Fig. 2. These latter are merely 
short lengths of steel wire bent as shown, 
so as to allow them freedom of motion up- 



wards. As can be seen one is for the pur- 
pose of signaling to the waiting tradesman 
that the housekeeper is coming, while the 
other performs an opposite function, as the 
case may be. 

Fig. 3 shows the indicator panel proper, 
which includes simply a low resistance gal- 
vanometer or ammeter, two push buttons, 
and a bell. If the reader cannot make such 
an instrument, he will hnd an admirable 
one described in the August issue of the 
"E. E." Of course, it is understood that 
the scale card is not marked off in amperes 
but instead into four divisions, numbered 
from one to four — each division represent- 
ing the title of such tradesmen as call most 
frequently. The front door device is also 
marked with corresponding numbers (see 
Fig. 2) and a printed card like that shown 
should be placed on it. It will be neces- 
sary to experiment for a while in order to 
have these numbers correspond; that is to 
say, when the switch is turned to Grocer, 
which is No. 1, the resistance traversed 
must be such as to move the needle on the 
indicator also to No. 1. Full electrical 
connections are shown in Fig. 4. 

Assuming that everything has been com- 
pleted, let us suppose the Milkman comes 
and turns the switch to No. 4. Such action 
allows more or less current to flow with 
the result that, at the same time the bell is 
rung, the indicator needle is turned also to 
No. 4 and all the lady of the house need 
do is to glance at the same to ascertain that 
fact. If milk is not wanted, she has only 
to push the button designated — Nothing 
To-day. The current set up actuates the 
electro-magnet controlling the lower signal 
and the latter is raised upwards, thus ac- 
quainting the tradesman with the fact that 
his goods are not required. At the same 
time, it will be noticed by following out 
the electrical diagram carefully, that the 
armature of the switch return mechanism is 
attracted upwards, thereby releasing the 
check pawl and allowing the switch (which 
has a coil spring exerting tension upon it) 
to resume its original position. The de- 
vice is then ready for the next caller. 

Contributed by JOHN T. DWYER. 
[Editor's Note : — We would suggest the use 
of a low resistance relay in place of the 
vibrating bell, the local circuit of the relay 
being connected to a bell and battery. This 
permits the action of the INDICATOR 
system to be much more even and accurate. 
This change in the layout is shown in sup- 
plemental diagram Fig. 4.} 

AN EXPERIMENTAL SPARK COIL. 

I have just completed a small "spark 
coil," of my own design, which embodies 
a special feature of regulation. The full 
strength of this coil, when the primary 
is all the way within the secondary, is Y?- 



e end piece 

tuoe 
I t'-fd fiber 

/ fa\ 

P/yrn 




f/der/i/de 



@ 



This Experimental Spark Coil Has a Re- 
movable Primary Coil and Core, So That All 
Sorts of Experiments Can Be Tried With It. 

inch heavy spark, and /the minimum 
Strength is "0," when the primary is drawn 
all the way out. 

The drawing explains all details. The 
primary is made separate and complete 
from the secondary with binding posts at- 



HOOK-UP FOR STARTING UP TWO 
MOTORS WITH ONE RHEOSTAT. 

Emergency making necessary the use of 
limited equipment for connecting up two 
10 horsepower direct current shunt field 
motors, with one starting box, I made use 
of the hook-up herewith reproduced to start 
up each machine and connect it on the main 
line. 

The first step was to provide ample pro- 




TPDT-7r/pIe po/e double throw switch 
R-r/?eostof, f* so omp.fuse. f- 100 amp. fuse 
S- shunf f/'eid. SS. - short/rig sw/fcf? 
fffiSJ' douMepote s/op/e throw srv/tcf/ © 



Useful Kink Utilizing One Starting Rheostat 
for Starting Up Two Motors. After Each 
Motor Has Been Accelerated in Turn, the 
Proper Switch Is Closed, Throwing It Di- 
rectly on the Line. 

tection against overloads and failure of 
power, which was overcome by properly 
fusing as per diagram. 

With T.P.D.T. switch in neutral or 
straight out position, connections to the mo- 
tor are broken. Throw main switch in, 
then T.P.D.T. to either side to start re- 
spective motor. Bring rheostat lever up 
slowly to no-voltage release and lock ; next 
throw in respective shorting switch, when 
handle on starter should drop, thus con- 
necting one motor on the line. 

To start the second motor, throw T.P.- 
D.T. switch to opposite side and start as 
before, after which close the proper short- 
ing switch. Both motors now on the main 
supply line; pull T.P.D.T. switch to neu- 
tral position. 

I have had entire success in running both 
motors by this method for a period of 
30 days, depending exclusively on the 30 
ampere fuses for overloads and manually 
opening the circuits in case of generator 
shut-down or cutting off of the power. 

Contributed by RAY J. BUTTON. 

tached. The secondary is wound upon a 
spool, which also has binding posts at- 
tache . 

The primary unit comprises an iron 
wire core 6 inches long by l A inch diame- 
ter. The primary winding is of two lay- 
ers No. 18 D.C.C. magnet wire. This is 
covered with several layers of waxed 
paper. The primary terminals are mounted 
on a fiber disc, 2 inches diameter, as 
shown. The completed primary is soaked 
in molten paraffin wax. The secondarv 
coil consists of l T i lbs. No. 34 S.C.C. mag- 
net wire, wound in layers onto a wooden 
or fiber spool, measuring 4 inches in length. 
The starting or inner lead of the secon- 
dary should be well insulated by passing 
thru a glass or rubber tube outside the 
spool or else by passing it thru a hole 
drilled radially down thru the spool cheek, 
this one being made r 4-inch thick or more 
for the purpose. 

Contributed by CHAS. S. PORTER. 



40 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



A Simple Electric Motor Attachment 
for Phonographs 

By R. U. CLARK, 3rd 



THE phonograph is without doubt one 
of the greatest of all pleasure giving 
instruments. This fact is amply 
demonstrated by the large number of these 
machines in use at the present time. It 
is, however, like many other articles, ap- 
preciated most when new, and is little used 



at a constant speed by the governor with 
which the talking machine is fitted, may 
appear rather inappropriate, but, altho 
some heating does take place in this motor 
it is not sufficient to cause excessive wear 
or shorten its life materially. 

The actual method of driving the talk- 




Illustrating How the Author Devised a Simple and Effective Electric Motor Drive for a 
Disc Style Talking Machine. The Old Governor Mechanism Is Retained and the Motor Drives 
the Record Table by Means of a String or Cord Belt. (Fig. 1.) 



after its novelty wears off, owing to the 
constant attention required to operate it. 
Winding up the spring to keep the motor 
going is the one thing which detracts most 
from the pleasure which should be derived 
from any good talking machine. 

By means of a simple electric motor at- 
tachment it is at once possible to do away 
with practically all the bother incident to 
the operation of the talking machine, with 
the exception of changing the records. 

Most of the standard machines on the 
market today lend themselves very readily 
to the attachment of an auxiliary motor 
device, so that, by the employment of a 
little care and ingenuity, it is a simple 
matter to remodel a phonograph so as to 
run it by electric motive power. 

The actual amount of power required 
to drive the turntable of most any phono- 
graph at the proper speed is very small, 
although it may not appear so to the per- 
son who has to be continually winding up 
the ordinary spring motor. Just how little 
power will suffice depends more or less on 
the machine to be driven, but for most 
machines a universal electric motor of 1/40 
H.P. will be found quite sufficient. These 
motors can be purchased new in most cases 
• for as little as $4 complete, and can be 
attached by a flexible wire direct to the 
ordinary lamp socket, without using any 
extra resistance. The motor used by the 
author with considerable success was 
bought originally as a fan motor for $4; 
the fan, guard, and base which came with 
the motor were removed. 

The motor mentioned above was de- 
signed to drive a six-inch fan at about 
3,000 r.p.m. Under this load the makers 
claim it can be run at a cost of about 1 
cent per 6 hours, the rate per K.W. being 
10 cents. This motor is equipped with 
special patented bearings which require no 
oiling; for about 2 months, during which 
time the author's machine has been run a 
great deal, no oil has been placed on the 
bearings. 

The use of such a small motor, as men- 
tioned above, for such exacting work as 
running a large turntable, which is held 



ing machine turntable on which the records 
rest, as described in this article, is by direct 
belt connection, which method requires 
perhaps the least accuracy in construction. 
The author after considerable experiment- 
ing with a simple friction drive, direct 
from the electric motor shaft, which was 
fitted up with various rubber and com- 
position friction wheels, was forced to 
give up this method in the favor of belt 
drive. Friction drive applied to such a 
mechanism as the phonograph requires 
very accurate construction, and even then 
direct friction drive on most machines 
would prove noisy and unsatisfactory, due 
to the notoriously imperfect, peripheral 
arc described by most talking machine 
turntables. 

The first step in the preparation of the 
talking machine for the addition of an 
electric motor is to run the machine until 
the spring is completely unwound. This 
requires about fifteen minutes time. The 
spring motor and top board is then re- 
moved temporarily from the phonograph, 
if possible, by removing the crank handle. 
In some machines it 
is possible to get at 
the motor from the 
bottom. As soon as 
access to the motor 
is obtained, the gears 
and shaft, which 
. form the connecting 
link between the 
turntable shaft and 
the spring motor 
gears are removed. 
The unit to be re- 
moved is clearly in- 
dicated in Fig. 1, A — 
A. The heavy cen- 
ter line A — A which 
passes thru the lower 
part of the spring 
motor casing indicates the position of the 
unit to be tr.ken out. Removing this; piece, 
by letting up on the set screws, which hold 
the pivot bearings, on which the shaft 
mentioned above runs, simply disconnects 
the turntable and its shaft from the spring 



motor, but does not effect the speed gov- 
erning mechanism, which is left in place, 
for use with the electric motor, to control 
the speed in the usual manner. 

After disconnecting the spring motor 
from the turntable shaft, the table should 
be removed and a small groove from 1/32 
to 1/16 of an inch deep, the actual depth 
depending on the thickness of the turn- 
table rim, should be made for the belt to 
run in around the outside of the rim. This 
groove should be about of an inch wide, 
and should not be too near the top edge 
of the rim. On certain machines there is 
a narrow shoulder located under the rim, 
which in some cases will hold the belt. 

As the phonograph is to be driven by a 
belt a small grooved pulley wheel for the 
motor is necessary. This wheel is best 
made of metal with a small groove about 
inch wide, either V or semi-circular in 
cross-section, and about 1/16 inch deep. 
The greatest diameter of the pulley should 
be about 1 inch or under. The author 
has used experimentally several sizes from 
Y% inch up to 1 inch, all with considerable 
success, but when a 1 inch wheel is used, 
the motor which then turns at about 800 
r.p.m. seems to run the quietest, and with 
practically no belt slippage. Within the 
sizes mentioned the diameter of the pulley 
will have little effect upon the speed of 
the turntable, which is still controlled by 
its own governor as mentioned above, but 
of course the motor pulley-belt speed will 
be decreased by the use of a small pulley 
and increased when a large pulley is em- 
ployed. A 10 cent pulley from a mechan- 
ical toy set is satisfactory. 

The metl.od to be used in mounting the 
motor will necessarily depend somewhat 
upon the type of talking machine used. 
There are two simple ways of attaching 
the motor, one of which should be appli- 
cable to nearly any machine made. Wher- 
ever the construction of the talking ma- 
chine permits, the motor can be hung out 
of sight, from the top-board of the body 
of the phonograph, with the shaft ex- 
tending thru this board about ^4 inch, 
so that the pulley wheel can be mounted 
with ease from the top side of the board 
on which the motor is hung, as shown in 
Fig. 1. This mode of mounting is possible 
only with a certain class of phonographs, 
mostly the larger sizes. For use with 
small machines, where the motor cannot be 
hung out of sight, it can be inverted and 
fastened to the top board, in such a man- 
ner that the pulley groove, which comes 
next in position to the motor bearing, 
with the hub near the outside end of the 
shaft, comes in line with the grooved por- 
tion of the turntable. (See Fig 2.) 

To use the method of attachment first 




Where it is Not Possible to Conceal the Motor in the Cabinet, as 
in Small Machines, the Motor Can Be Readily Mounted Above the 
Cabinet Shelf as Shown. (Fig. 2.) 



described it is necessary to drill three holes 
in the top board spaced about 2 inches 
from the edge of the turntable. The 
center hole is made to accommodate the 
main bearing and shaft of the motor. The 
(Continued on page 76) 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



41 




WOT 
llWliJ 




TV"? 





This department will award the following monthly prizes: First Prize, $3.00; Second Prize, $2.00; Third Prize, $1.00. 

The purpose of this department is to stimulate experimenters towards accomplishing new things with old apparatus or old material, and for the most useful, 
practical and original idea submitted to the Editors of this department, a monthly series of prizes will be awarded. For the best idea submitted a prize of $3.00 is 
awarded; for the second best idea a $2.00 prize, and for the third best a prize of $1.00. The article need not be very elaborate, and rough sketches are sufficient. We 
will make the mechanical drawings. Use only one side of sheet. Make sketches on separate sheets. 



FIRST PRIZE, $3.00 



A VOLTMETER FOR THE AMA- 
TEUR ELECTRICIAN. 

Herewith is described an easily construct- 
ed voltmeter, which will accurately register, 




A Simple Voltmeter for the Student, Com- 
prising an Electro-magnet and a Pivoted 
Piece of Sheet Iron With an Indicating Needle 
Attached as Shown. 

if properly constructed and adjusted. It is 
very simple and requires few materials, all 
of which are found around the experiment- 
er's shop. 

The base was made 5 by V/ 2 by ]/> inches. 
The upright U was made from the same 
material 1 inch shorter. Next I cut out a 
piece of tin from a cocoa can in the shape 
shown in Fig. 1; 2 inches from 1 to 1, 1 
inch from 2 to 2 and \ l / 2 inches from 3 to 3. 
Two small holes are put one in each end. 
Then I bent it into the shape shown in Fig. 
2, over a hammer handle. The pointer P 
was made from a piece of fine wire and 
soldered on. A large pin served as an axle, 
H. The piece of tin A, Fig. 3, holds one 
end of the pin while the other end is driven 
into the upright, U. The magnet M was 
taken from an old bell and held in position 
by tin strips as shown. After putting the 
binding posts, P, on and fastening the up- 
right and disk into position, the instrument 
was complete. 

The best way to mark the disk is with a 
transformer; mark where the pointer stays 
in a natural position with an O Then con- 
nect five volts to the binding posts and 
mark where the pointer stays with a 5. Do 
the same with ten and fifteen volts. Mark 
off spaces of one volt each between the 
numbers. This instrument will be an inter- 
esting as well as useful addition to the 
shop for measuring various voltages. 

Contributed by FRANK M. JACKSON. 

GOLD LEAF SUBSTITUTE FOR 
ELECTROSCOPES. 

Coat lightly one side of a piece of tis- 
sue paper with lamp black and turpentine 



SECOND PRIZE, $2.00 



USING COMMUTATOR FOR WIND 
DIRECTION INDICATOR. 

Many people find an electrical wind di- 
rection indicator both useful and practi- 
cal. It is very convenient to have such 
an installation in the home, office or lab- 
oratory, so that by simply glancing at the 
electrical annunicator, one may know just 
how the wind is blowing, so far as its 
direction is concerned. 

Most of those described in the "How- 
To-Make-It" columns of electrical jour- 
nals, involve the construction of a com- 
mutator or segmental switch. This diffi- 
culty is readily overcome by utilizing a 
small size motor commutator, which can 
be purchased at little cost from any elec- 
trical supply house or dealer, and having 
eight or more segments. 

The commutator is made stationary on 
the shaft standard supporting the weather 
vane, while the moving lower part of the 
device attached to the weather vane 
proper, carries at its lower end an elec- 
trical contact brush (preferably a rolling 
ball or wheel contact) which of course 
will turn with the vane. 

The moving part of this apparatus 
should not be too stiff, and the best ones 
now in use are equipt with ball bearings. 
With a little ingenuity on the part of the 
builder, it will be found possible to in- 
corporate the ball bearing feature with 
very little trouble, and the vane will be 
many times more accurate and reliable 
than the ordinary one. The circuit con- 
nections between the moving brush, com- 
mutator and flash lamp annunciator are 
shown. 

Contributed by PETER BROWN. 




Many Experimenters Desire to Build an 
Electrical Weather Vane, But Hesitate to 
Do So, Owing to the Difficulty in Construct- 
ing a Suitable Multiple Contact Switch. A 
Motor Commutator Solves the Problem. 

with a brush. Cut a 2V 2 x I 4 inch piece 
from it for your electroscope. Electro- 
scopes may be used to test insulators. 
Contributed by 

CLARENCE MELOTZ. 



THIRD PRIZE, $1.00 



WHAT IS A SAFE RETREAT 
DURING A THUNDERSTORM? 

Place a mouse, a bird, an electroscope 
and some gunpowder inside a wire gauze 
cover, such as is used for protecting meat. 



To tfat/c mac/7 




G/osj tumblers 



To Prove That a Person Is Invariably Safe 
from Lightning When Inside a Metallic Cage, 
Mr. Weinbrot Places Some Powder, a Mouse 
and a Bird Within a Metal Cage. Heavy 
Static Sparks Jumping to the Cage from a 
Wimshurst Machine Have No Effect on Any 
of Them. 



The whole, being placed on a board is 
supported on four warm, dry tumblers 
placed on the top of a table. 

Connect it with a static machine and set 
it working. Altho an abundance of sparks 
may be made to play all over the out- 
side, the living things, the gunpowder 
and even the electroscope will not be af- 
fected in the least. 

From this experiment one may therefore 
deduce that the safest place in a thunder- 
storm is in the metal lined meat safe, pro- 
vided, of course, that it is large enough. 
This also demonstrates the theory of Lodge 
regarding the design of lightning rods for 
protecting buildings. Lodge recommends 
for first-class protection that the edifice 
should be entirely enclosed under a per- 
fect network of wires, resembling in effect 
an ordinary bird cage. Modern installations 
of lightning rods follow this theory as 
nearly as possible. The important part to 
bear in mind is, that you should not touch 
the metal, otherwise fatal results will oc- 
cur. 

Contributed by E. F. WEINBROT. 



FROSTING GLASS WITH BEER. 

Secure y 2 pint of lager (light or dark) 
beer, and to this add enough epsom salts, 
so that when stirred up it will be the con- 
sistency of cream. Apply this cream to the 
glass to be frosted with a sponge. This 
frosting will not readily wear or rub off un- 
der any conditions. 

Contributed by EUGENE RUCKMAN. 



4 2 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



HOW TO KNOW WHEN TOOLS 
ARE RETURNED. 

Every experimenter knows that people 
who come in and borrow tools never, by 




To Tell at a Glance Whether or Not a Cer- 
tain Tool Has Been Returned, Simply Paint 
Its Outline in Black or White on a White 
or Black Board as Shown. 



any chance, replace them in their proper 
place. 

The accompanying illustration shows a 
very simple method of overcoming this an- 
noyance. The outlines of the tools are 
painted in white or black on the cabinet 
wall in the positions which the tools nor- 
mally occupy. When this is done a person 
has only to glance at the cabinet and can 
tell immediately just where each tool be- 
longs. 

Contributed by 

AN EXPERIMENTER. 



A SOUND OPERATED MOTOR. 

Take any telephone transmitter and re- 
move the carbon granule cup, solder a plat- 
inum point to any metal piece and fasten 
in place of the granule cup. Solder a plat- 
inum point to the center of the diafram. 
The two platinum points should be as near 
each other as possible without touching. 
The battery motor is equipt with a wood- 
en block fastened to the axle shaft. A 
mirror can be fastened on either side of 
the block. A beam of light can thus be 
reflected, which should prove interesting 
to those experimenting with sound waves. 
The motor and transmitter are placed in a 
circuit with a battery. 

Any word spoken into the transmitter 



D/ophrogm 
( 



Baft 

Ptot/numJ iiyj| \^ 
points 



Mirror 




Novel Scheme for Controlling Revolving 
Mirror by Means of a Microphone. 

will vibrate the diaphragm, and cause the 
motor to spin around at different speeds, 
according to the words spoken. 



PRACTICAL HELPS FOR THE 
AMATEUR. 

Repairing Dry Cell Terminals. — A simple 
method is to solder a 6-inch length of flex- 
ible wire to the zinc container of the dry 
cell for making connections. If a binding 
post is necessary, solder a spring binding 
post in place as shown. In emergencies 
paper clips may be used, bending as shown 
and slipping wire into them. 

Shocking Machine from Alarm Clock. — 
Since a clock is generally used as an in- 
terrupter best results can be obtained by 
arranging a spring to press against one 
of the wheels which revolve at fairly high 
speed, when the balance wheel is removed. 
A higher rate of interruption results, giv- 
ing a constant tingle instead of a series of 
jerks. The spring and gear are connected 
in series with two handles, an electromag- 
net and two to three dry cells. 

Simple Time Signal. — The relay and re- 
sistance shown in a previous issue of this 
journal may be done away with by simply 
rewiring the time ball solenoid and horn as 
shown herewith. This likewise does away 
with an extra set of batteries. Key B 
operates the electric horn and A controls 
the semaphone. 

Removing Enamel from Magnet Wire. — 
The easiest method is to use an ink eraser 
for this purpose. The wire is cleaned 
quickly and perfectly without excessive 
abrasion. To do this easily, slit one end 
of the eraser and run the wire thru the 
slit several times. 

Fuse Clips. — This fuse is in the same 
class as the above hints, being made from 




Contributed by 



LEE A. COLLIXS. 



Some Handy Kinks for the Experimenter. 



paper clips. Fasten to board with screws 
or tacks and slip fuse wire, fine copper 
wire or tinfoil under clip. 

Contributed by T. W. BEN SOX. 

A CLEVER USE FOR SPEED INDI- 
CATORS. 

In constructing a metal pattern recently 
in order to determine the amount of metal 
needed for a wall, it became necessary to 
find the perimeter of a figure similar to 
that shown in Fig. 1. The work was held 
up until a way of doing this could be found. 
I at last thought of the following device : 

A brass wheel. -)4 inches in diameter, was 
soldered on the shaft of an_ "Electro" 
Speed Counter as shown in Fig. 2. The 
counter was then grasped in the hand and 
the wheel was run around the edge of the 
design. The diameter of the wheel was 
multiplied by 3.1416 to obtain the circum- 
ference of the wheel, which was then mul- 
tiplied by the revolutions shown on the in- 
dicator. This gave the distance around the 
figure. The size of the wheel can of course 
be altered to suit different conditions. 

Contributed by J. C. GILLILAND. 

[Editorial Note: — Another useful dodge 



A HANDY HEIGHT GAGE. 

The sketch gives dimensions for making 
this useful height gage. The micrometer 
head is of Brown & Sharpe make and will 
give a forced fit in the .374" hole. It will 
be necessary to anneal the spindle end to 
tap a No. 3-48 thread, so as to hold the 




An Effective Precision Height Gage May Be 
Constructed from a Standard Micrometer 
Head Fitted in a Steel Base of the Dimen- 
sions Indicated. 

linger shown in detail at the right, also 
the screw. The bottom surface of the base 
is undercut 1/16 leaving a 3/16 foot all 
around. 

Harden the finger, screw and base, and 
when finger is attached to spindle it is 
moved all the way to zero on barrel ; that 
is, when tapping, base and finger are to- 
gether, the micrometer head is set at zero, 
all moving parts having a free sliding fit 
with no shake. 

This gage has one advantage over the 
great number of other height gages in that 
you can scratch a line from O to any rea- 
sonable dimension. 

Contributed by JAMES McIXTYRE. 

ill this direction consists of making a brass 
wheel as shown at Fig. 3, having a small 
groove in its perifcry; in this groove is 
placed (glued) a rubber band which is 
slightly smaller than the wheel. Knowing 
the dimensions of this wheel and noting 
the revolutions on the dial, it becomes an 
easy matter to measure railroad lines, state 
border lines, conduit and pipe runs on blue- 
prints, ct cetera, by simply rolling the 
wheel along these lines. In one of these 
devices which we used some time ago, the 
wheel was made so as to have a circum- 
ference of 5 inches, or a maximum diame- 
ter of about 1% inches. The diameter 
multiplied by 3.1416, gives the circumfer- 



15 9 7 





F/g.Z 




Brass wtiee/ 

for 

rudder band 

rMber 



Bore to f ft 
shaft fgfrf/t/ 



fig. 3 



Attachment for a Speed Indicator Making It 
Available for Measuring the Perimeter of 
Irregular Surfaces, Map Routes, etc. 

ence and the latter term, divided by 3.14161 
gives us the diameter.] 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



43 



Experimental Chemistry 

By ALBERT W. WILSDON 
Twelfth Lesson 



ACIDS, BASES, AND SALTS. 

IN this lesson we shall take up the 
study of the various acids and char- 
acteristics. These form one of the 
most important studies in the realm 
of chemistry. A resume of the gen- 
eral properties of acids are briefly as fol- 
lows : 




How Apparatus Is Arranged in Experiment of 
Collecting the Product of Acetic Acid. 



1. An acid is a substance composed of 
hydrogen and a non-metallic element or 
radical, the hydrogen being replaceable by 
a metal or a group of elements equivalent 
to a metal. The fact that hydrogen is a 
constituent of all acids, explains why they 
are sometimes called Salts of Hydrogen. 

2. Acids usually have a sour taste. 

3. Tf soluble in water, as most acids are, 
they turn blue litmus paper (or solution) 
red. They also change the color of man} 
vegetable substances. 

4. They react readily with a base to 
form a salt and water. 

5. They react readily with some metals 
to form salts, liberating hydrogen. 

6. Most acids are soluble in water. 

7. They also have the power to decom- 
pose most carbonates, like limestone, lib- 
erating carbon dioxid which escapes with 
effervescence. 

The common acids are: 
Hydrochloric (HC1): Xitric (HX0 3 ) ; 
Sulfuric (H..SCM; Acetic (C 2 H 4 OJ ; Ox- 
alic (H 2 C 2 4 ) ; Tartaric (H 2 C 4 H„0 4 ) and 
Citric (C 6 H 8 0t); 

Of these common acids, Hydrochloric is 
a gas (the Hydrochloric or Muriatic acid 
of commerce is only the gaseous acid in 
solution) : Sulfuric and Nitric acids are 
liquids : while Oxalic, Tartaric, and Citric 
acids are solids. 

To illustrate the many familiar sub- 
stances which are acids or contain them, 
we will take the following few : 

Vinegar, Pickles and Relishes, when Ace- 
tic acid is present, attributes to the agree- 
able sour taste. 

Vinegar is simply a dilute solution of 
acetic acid, containing coloring matter and 
other substances, obtained by the acetus 
fermentation of poor wine or wine resi- 
dues, of beer which has turned sour, and 
of other dilute alcoholic liquids. 

The sourness of fruits being due to the 
presence of citric acid, as in the lemon, 
rpnle, currant, r spberry, gooseberry, etc. 

During fermentation many acids are 
formed, as in the case of sour milk, lac- 
tic acid is present 



Soda water is a solution of Carbonic 
acid (Carbon Dioxid), and acid phosphate 
is a solution of a sour calcium phosphate. 
.Mineral waters frequently contain Car- 
bonic acid. 

Hydrochloric acid is present in the gas- 
tric juice of the stomach, and performs 
an important part in the process of diges- 
tion. 

From the above we can see that many 
acids are of importance, and many are 
used by us every day in some form or 
other. We can, therefore, see that all 
acids are not to be scorned as danger- 
ous, as doubtless many readers of this ar- 
ticle have heretofore believed, when the 
word acid was mentioned. 

NOMENCLATURE OF ACIDS— 

Oxygen is a component of most acids, 
and the names o! these acids correspond to 
the proportion of oxygen which they con- 
tain. The best-known acid of an element 
usually has the suffix -ic, as Sulfuric, Nit- 
ric, Phosphoric. If an element forms an- 
other acid containing less oxygen, this acid 
has the suffix -ous, as, Sulfurous, Chlorous, 
Phosphorous. Some elements form an acid 
containing less oxygen than the -ous acid; 
these acids retain the suffix -ous, and 
have, also, the prefix Hypo-, as, Hyposul- 
furous, Hypophosphorous, Hypochlorous. 
The prefix Hypo- is derived from the 
Greek word, meaning lesser or under. If 
an element forms an acid containing more 
oxygen than an -ic acid, such an acid re- 
tains the suffix -ic and has, also, the pre- 




ln Conducting Experiments With Various 
Acids it Will be Found Convenient to Place 
the Test Tubes Containing the Acids in a 
Wooden Rack. The Tubes May Be Suitably 
Labeled. 



fix Per, as, Persulfuric, Perchloric. The 
Latin prefix meaning beyond or over. The 
few acids which contain no oxygen have 
the prefix Hydro- and the suffix -ic, as, 
Hydrochloric, Hydrobromic, Hydrofluoric. 
It should be noticed that these suffixes are 
not always added to the name of the ele- 
ment, but often to some modification of it. 

Acids having the prefix Hydro- and end- 
ing in -ic form salts with names ending in 
-ide and having no prefix. 

All other acids with names ending in -ic 
form salts with names ending in -ate. 
[Final "e" dropt in simplified spelling.] 

All acids who.e names end in -ous, form 
salts. whose names end in -ite. 

ACIDS AND THEIR SALTS. 

Hydrochloric acid. HC1; Form Chlorids, NaCl; 
Sodium Chlorid. 
Sulfuric acid. H?SO<<; Form Sulphats, CUSO4; 

Coiper Sulphat. 
Nitric acid, HNOj; Form Nitrats Pb[N0 3 ]2; 
lead Kitrat. 
Sulfurous acid, H^SO^; Form Sulphits, K2SO3; 

Potassium Sulphit. 
Hydrobromic acid, HBr: Form Bromide, AgEr; 

Silver Bromid. 
Carbonic acid, H2CO3; Form Carbonats CaCO^; 
Calcium Carbonat. 
Hydrosulfuric acid. H3S: Sulphids, ZnS; 
Zinc Sulphid. 



Hydroiodic acid, HI; Form Iodids, Kl ;Potassium lodid 
Nitrous acid. HNO2; Nitrits, NaNCb; 
Sodium Nitrit. 
Phosphoric acid, H3PO4; Form Phosphats, FePCj; 
Iron Phosphat. 
Hydrofluoric acid, HF; Form Fluorids, CaF2; 

Calcium Fluorid. 
Chloric acid, HCIO3; Form Chlorats, KCIO3; 
Potassium Chlorat. 

The nomenclature of acid, is well illu - 
trated by the scries of chlorin acids: 



Name. Formula. 

Hydrochloric HC1 

Hypochlorous HCIO 

Chlorous '. HCIO2 

Chloric HCIO3 

Perchloric HCIO4 



Not all elements form a comp'.ete series 
of acids, but the nomenclature usually 
agrees with the above principles. 

An examination of the formulas of acids 
show that all do not contain the same num- 
ber of hydrogen atoms. Acids are some- 
times classified by the number of hydro- 
gen ;>toms which can be replaced by a 
metal. The varying power of replaceability 
is called Basicity. A Monobasic Acid con- 
tains only one atom of replaceable hydro- 
gen in a molecule, as Xitric Acid HXO. 
A molecule of Acetic acid (C 2 H 4 2 ) con- 
tains four atoms of hydrogen, but for rea- 
sons which are too complex to state here, 
only one of these atoms can be replaced by 
a metal. Dibasic and Tribasic Acids con- 
tain two and three replaceable atoms, as, 
Sulfuric acid (H 2 SOi) and Phosphoric 
acid (H,POi ). Obviously, monobasic acids 
form only one class of salts, dibasic acids 
form two classes, tribasic acids form three, 
etc. 

EXPERIMEXT XO. 51 

Fill a test tube one-third full of either 
Hydrochloric Acid (diluted), or Sulfuric 
Acid (diluted). Fill another test tube one- 
third full of concentrated acetic acid. In 
some manner label the tubes for identifica- 
tion of the contents. 

Try the action of a drop of the acid on 
both red and blue litmus paper. 

Drop a small piece of zinc or other metal 
into each tube successively. If no chemi- 
cal action results, warm gently. Test for 
the most obvious product (hydrogen) by 
holding a lighted match at the mouth of 
each tube. If no decisive action results, 
provide the test tube with a stopper and 
simple delivery tube, and collect any pro- 
duct in a test tube over water. This lat- 




Simple Method of Dropping Liquids by Means 
of a G ass Rod Held in the Hand. 



ter method will probably be unnecessary 
except with the acetic acid. 

(Continued on page 52") 



44 



THE ELECTRICAL EXPERIMENTER 



May, 1917 




Under this heading we publish every month use- 
ful information in Mechanics, Electricity and 
Chemistry. t We shall be pleased, of course, to 
have our readers send us any recipes, formulas, 
wrinkles, new ideas, etc., useful to the experi- 
menter, which will be duly paid for, upon pub- 
lication, if acceptable. 



EXPERIMENTER'S APHORISMS 
In the following, we wish to give to the 
Experimenter some hints as to the use of the 
different ingredients and how to work them: 

(1) Always bear in mind that exact working 
of a formula requires ACCURACY, CLEANLI- 
NESS, PATIENCE, and SKILL. 

(2) Know what you are about, before you start 
to experiment. 

(3) "THE HISTORY OF FAILURES IS THE 
HISTORY OF SUCCESS" goes an old adage, and 
it applies well to the experimenter. 

(4) Many times impure, wrong or deteriorated 
raw materials, spell FAILURE instead of SUC- 
CESS. 

(5) A great many of the chemicals and in- 
gredients requited, cannot be obtained from 
drug stores; buy them at a reputable supply 
house. 

(6) BEFORE CONDEMNING A FORMULA, be 
sure the fault does not lie with the manner of 
handling it, or the purity of the ingredients. 

(7) Be sure to mix the materials comprising 
a certain formula in the proper sequence. 

(8) When starting to prepare a mixture, 
especially one containing liquids, ask yourself: 
"IS THE SPECIFIC GRAVITY CORRECT, AS 
INDICATED BY A HYDROMETER? IS THE 
TEMPERATURE RIGHT? IS THE QUANTITY 
OR WEIGHT RIGHT? 

(9) Acids and water, when mixed, should be 
manipulated in the proper manner, i. e., THE 
ACID SHOULD BE POURED INTO THE 
WATER, and not vice versa, as the solution is 
liable to be forcibly ejected from the containing 
vessel and into the mixer's face. 

(10) For any kind of SYSTEMATIC WORK, 
a floating THERMOMETER and HYDROM- 
ETER, as well as measuring glasses and 
scales, should always be provided, as GUESS- 
WORK is EXPENSIVE, and SOMETIMES 
FATAL. 

(11) Put labels on ALL bottles, boxes and 
packages with FULL INSCRIPTION as to their 
contents, it will avoid troubles and mistakes. 

(12) Remember that a beginner cannot expect 
to make articles AT FIRST, which will com- 
pare with regular manufactured products. S.G 



CHEMICAL EXPERIMENTS. 

I have been experimenting a little and 
have found that an infusion of logwood 
chips and water will change color when 
other chemicals are added. 

Take three glasses Xos. 1, 2 and 3 and 
prepare them as follows : Rinse Xo. 1 
with strong vinegar ; Dust Xo. 2 with 
powdered alum ; Rinse Xo. 3 with a solu- 
tion of copper sulfate. The next step is 
to pour the logwood into each. If the 
glasses have been prepared correctly the 
logwood in Xo. 1 will fade to a pale yel- 
low. That in Xo. 2 will become almost 
black and that in Xo. 3 will change to a 
pale purple. This is the principal set of 
changes but following is a list of changes 
using not only logwood but also other 
chemicals. Some of them can be used as 
stated above but in the case of ammonia 
for instance, the odor would give it away. 

Color changes that are due to chemi- 
cal action : 

1. — Logwood, ammonia and copper sulfate 
gives a brown. 

2. — Logwood, vinegar and ammonia gives 
purple. 



3. — Logwood, alum and ammonia cause 
a red precipitate. 

4. — Logwood, vinegar and copper sulfate 
gives a brown. 

5. — Logwood, ammonia and common salt 
gives a light brown. 

6. — Logwood, copper sulfate, common 
salt, and alum mixed give a pink. 

7. — Phenolphthalein and ammonia gives 
a bright red (test for free ammonia). 

8. — Copper sulfate and ammonia gives a 
bright blue (test for copper sulfate). 

9. — Logwood and hydrogen peroxid gives 
a pale yellow. 

10. — Logwood, copper sulfate and caustic 
soda gives a pale blue precipitate. 

These are the results as far as I have 
gone but I hope to continue my work and 
get different results. 

Contributed by W. B. SPURRIER. 



HANDY APPARATUS FORMED 
ENTIRELY OF WIRE. 

As shown in the accompanying sketches 
a number of useful articles of constant 
service to the experimenter may be con- 
structed of ordinary wire with the aid of a 
few common tools. 

Obtain a few feet of galvanized iron wire, 
or if the item of expense is not important, 
brass wire ; 3 or 4 gage numbers are re- 
quired, depending upon the size of the 
apparatus to be constructed. 

Provide a pair each of flat, round and 
cutting pliers, some wood sticks about the 
dimensions of a lead pencil, and a few 




Numerous Handy Devices for Holding Test 
Tubes and the Like Can be Easily Con- 
structed from Wire with a Little Ingenuity. 

short lengths of tubing to aid in bending 
and forming the wire; after a few ex- 
periments you will be able to determine 
the size of the wire best adapted. 
Cork Puller. 
Figure 1. — Cut two pieces of wire the 
desired length, twist together and form 
ring. Xow twist the four ends to about 
one-third the length of the shank. Make 
separately a ring of sufficient size to fit 
loosely over the shank, cut wires of shank 
to same length and bend ends to a right 
angle about % inch. Slip on the ring 
and spring the four ends apart to keep 
ring in position. The completed article 
will be found of service in removing corks 
which have fallen into the container, and 
by placing a piece of cotton in the jaws a 
most' useful instrument is formed for the 
cleaning and drying of test tubes. 

Holders. 

Figures 2 and 3. — Follow outline of 
sketch to obtain good results. Twist wires 
together 3 or 4 times, allowing but very 
little play. Bend the four ends at a straight 
angle and form the ring at the end of tool 
by bending wire around a rod of the re- 
quired size. 



CHEMICAL SUBSTANCES — THEIR 
TECHNICAL AND COMMON 
NAMES. 

Xearly all of the chemicals in common 
use to-day have more than one name, and 
the purpose of this list is to classify some 
of the most common ones in use for the 
benefit of the amateurs who sometimes be- 
come confused in the different names. The 

Aqua Fortis Nitric Acid. 

Aqua Regia Nitro-Muriatic Acid or Nitro- 

Hydrochloric Acid. 

Blue Vitriol Sulfat of Copper. 

Cream ol Tartar Tartrate of Potassium. 

Calomel Sub-Chloride of Mercury. 

Chalk Calcium Carbonate. 

Salt ot Tartar Carbonate of Potassium. 

Caustic Potassa Hydrate Potassium. 

Chloroform Chlorid of Formyle. 

Common Salt Chlorid ot Sodium. 

Copperas, or Green Vitriol. . .Sulfate ot Iron. 

Corrosive Sublimate Bi-Chlorid of Mercury. 

Dry Alum Sulfate Aluminum and Potas- 
sium. 

Epsom Salts Sulfate of Magnesium. 

Ethiop's Mineral Black Sulfid of Mercury. 

Galena Sulfid of Lead. 

Glauber's Salts Suhate of Sodium. 

Iron Pyrites Bi-Sulfid of Iron. 

Jewelers Putty Oxid of Tin. 

Kings Yellow The Sulfid of Arsenic. 

Laughing Gas Protoxid of Nitrogen. 

Lime . .Oxid of Calcium. 

Lunar Caustic Nitrate of Silver. 

Muriate of Lime Chlorid of Calcium. 

Niter of Saltpeter Nitrate of Potash or Potas- 
sium Nitrate. 

Oil of Vitriol Sulfuric Acid. 

Realgar Bi-Sulfid of Arsenic. 

Red Lead Lead Oxid. 

Rust ot Iron Iron Oxid. 

Sal-Ammoniac Muriate of Ammonia. 

Slacked Lime Hydrate Calcium. 

Soda Oxid of Sodium. 

Spirits 01 Hartshorn Sesquicarbonate of Ammo- 

ium. 

Spirits of Salt Hydrochloric or Muriatic 

Acid. 

Stucco of Plaster of Paris ... . Sulfate of Lime. 

Sugar of Lead Acetate -of Lead. 

Verdigris Acetate of Copper. 

Vermillion Sulfid of Mercury. 

Vinegar Acetic Acid (dilute). 

Volatile Alkali Ammonia. 

Water Sub-Oxide of Hydrogen. 

White Vitriol Sulfate of Zinc. 

chemicals in the two lists opposite each 
other are the same under a different name. 
Contributed by EARL BOTTEN. 



Spring Holders. 

Figures 4 and 5. — Use very thick and 
springy wire; will be found of service in 
holding articles to be soldered or ce- 
mented. It will be observed from sketch 
that device in figure Xo. 4 holds by itself, 
while the reverse is true of Xo. 5 design. 
The ends of these holders can be made 
pointed or flattened as preferred. 

Figure 6. — Holder for rubber tubes. Ob- 
tain a piece of thin wire. First bend it in 
two, making a loop to allow a hook to 
hold it in place. Then wind wire around 
a rod of proper size. Slip tube thru spiral 
so formed. This device will not permit 
tube to kink or bend at an angle sufficient 
to kink or to fracture. 

Figure 7. — Holder for articles to be sol- 
dered or heated. The slight pressure ob- 
tained by allowing the straight bend to 
pass a little thru the ring will be found 
sufficient to hold the articles in a position 
convenient for operation. 

Figure 8. — Tripod to support retorts. 
This article is formed by twisting three 
wires together forming a stand as shown 
in sketch. 

Figure 9, 10 and 11.— Battery connectors. 
Figure 10 can be fastened to table by put- 
ting a screw or nail thru ring at its 
end. In the event of the contact jaws 
becoming loose they can be adjusted by 
drawing the ends closer together. The 
line wires can be soldered to the connec- 
tors, and if desired the connection on 
figure 11 can be covered with insulating 
tape. 

Figure 12. — Very light weights. Each 
bend increases 1 centigram or 1 decigram,, 
varying according to the size of wire used. 

Contributed by 

AX EXPERIMEXTER. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



45 




Our Amateur Radio Station Contest is open to all readers, whether subscribers or not. The photos are judged for best arrangement and efficiency 
of the apparatus. To increase the interest of this department we make it a rule not to publish photos of stations unaccompanied by that of the owner. Dar.jc 
photos preferred to light toned ones. We pay each month $3,00 prize for the best photo. Make your description brief and use only one side of the sheet. 
Address the Editor, "With the Amateurs" Dept. 



AMATEUR RADIO STATION 
CONTEST. 
Monthly Prize, $3.00. 
This month's prize-winner. 

RADIO STATION OF FRED DIETZ, 
PHILADELPHIA, PA. 

I present here a flashlight photo of my 
station. The aerial is forty feet high, one 
hundred feet long, composed of three wires 
spaced six feet apart. 




Long Wave Radio Station of This Month's 
Prize Winner — Mr. Fred Dietz, of Philadel- 
phia, Pa. He Hears the German Stations 
and Many Others. 

The sending set consists of a V/2 inch 
Manhattan spark coil, Murdock sending 
condenser, spark gap and key. I also have 
a six volt storage battery, and can send 
fifteen miles. 

The receiving set consists of two loose 
couplers, one tunes up to two thousand me- 
ters and the other to three thousand meters. 
The small loose coupler is used with a crys- 
tal detector. The large loose coupler is 
used on the Audion and Audio-tron. I use 
three Bunnell variable condensers, three 
loading coils and a pair of Murdock 
'phones. I can hear OUI, POZ, NBA 
(Darien, Panama), NAT (New Orleans), 
NAR (Key West J ; and a great many other 
land and ship stations, on undamped waves. 
I can hear as far as Key West on a crys- 
tal detector. My call number is 3GA. 

Philadelphia, Pa. FRED DIETZ. 



THE FIRST "RADIO" MESSAGES. 

At the battle of Ishtib a Bulgarian cow- 
herd signaled news to his military coun- 
trymen relative to the position of the Ser- 
bian battalions by moving five cows about 
in various ways on the top of a hill. 

The Basutos, by the way, practically an- 
ticipated "wireless telegraphy" in a crude 
fashion. That is, by striking heavily on a 
huge drum of goat skin, which is placed 
on a special spot, another Basuto at a dis- 
tance can gather the purport of the mes- 
sage by placing his ear close to the ground 
to catch the vibrations, and he in turn 
passes the message on. 

Of course, given suitable climatic condi- 
tions, the military heliograph can transmit 
messages over enormous tracts of coun- 
try, and the record is probably held by an 
Englishman, Captain Sadler, of the Sixth 
Dragoon Guards, who, by this means, suc- 
ceeded in South Africa in sending a mes- 
sage direct a distance of 130 miles. 



WALTER LITRE'S EFFICIENT 
RADIO STATION. 

I have been reading your valuable maga- 
zine for the past two years, and have been 
greatly interested in the photos of ama- 
teur stations which you publish monthly. I 
submit two photos, one of my station and 
one of my aerial. My sending set consists 
of an E. I. Co.'s Vi k.w. transformer, a 
Murdock oscillation transformer, a Mar- 
coni key, straight spark gap, a photographic 
plate condenser consisting of ten plates, 8 
by 10 inches, with tin-foil between cut 6 by 
8 inches. 

The receiving set consists of an Arnold 
Navy type loose coupler of 2,500 meters, 
Holtzer-Cabot 3,000 ohm 'phones, Clapp 
Eastham fixt condenser, Alurdock variable 
condenser, Bunnell detector, and an aerial 
switch. My aerial is made of seven strand 
copper wire with a twenty foot- mast at one 
end and a thirty foot one at the other. The 




aerial is 75 feet long. I have not received 
my official call from the Government yet, 
but have my application in. 

WALTER E. LITKE. 

Fordham, N.Y. 



ELECTRIC HAND GENERATOR 
DETONATES DYNAMITE. 

An electric generator small enough to 
be carried in a man's pocket, yet powerful 
enough to discharge dynamite blasts, has 
been invented. 



[1 ATTENTION!!! [I 

|| Has your station photo appeared in II 

|| "The Electrical Experimenter"? Why || 

|| not purchase the electrotype and have || 

|| some "real" stationery printed with II 

|| youi station picture on it? All of the || 
|| "regular radio-bugs" are doing it. 

^ """ ""• ,,,,!!!!!!!, ,!!ii!!!!!!!!!m!!!!!!!l!!!!'!!!lml!!!,„Mi,„„uS 



RADIO JOINS SAMOAN ISLANDS 
WITH UNITED STATES. 

Construction of another government 
wireless plant, connecting the United 
States with its insular possessions, has 
been completed at Tutuila, placing the 
Samoan Islands in direct communica- 
tion with the outside world for the first 
time since their acquisition by the U.S. 

The station at Tutui! . connects with 
Honolulu, where a great plant commu- 
nicates with San Diego, Cal. Governor 
Poyer, of the Islands retired naval offi- 
cer, advised Secretary Daniels on Feb- 
ruary seventeenth of the completion of 
the plant and transmitted a message 
from the native chiefs. 



LEONARD NIESSEN A COMING 
"RADIO-BUG." 

The sending set consists of a one-half 
inch spark coil, plate and Leyden jar con- 
denser, oscillation transformer, spark gap 
and key. 

The receiving set consists of a Murdock 
loose coupler, fixt condenser, galena and 
silicon detectors, Brandes' 2,000 and E. I. 
Co.'s 2,000 ohm 'phones and a buzzer test. 

The vertical rod seen under the center of 
the table is an automatic closing lightning 
switch, operated by a foot lever, the switch 
itself being outside on the wall of the 
house. Most of the apparatus is of my 
own construction. The aerial consists of 
six wires spaced two feet apart on twelve 
feet spreaders, fifty feet long and forty 
feet high. 

I am a member of the Milwaukee Radio 
Association, also the Central Radio Asso- 
ciation and hold a first grade Amateur Li- 
cense. Call "9AKC." . 

Have been a subscriber to The Elec- 




trical Experimenter for the last two years 
and have benefited greatly by reading it. 

LEONARD P. NIESSEN. 
Milwaukee, Wis. 



46 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



PAUL RALSTON'S RADIO 
STATION. 

With the exception of the pair of Bran- 
ches' phones, a l /i k.w. Packard trans- 
former and the rotary gap motor, this set 
is all of my own construction. 




Paul Ralston, of Conneaut Lake, Pa., Is an 
Ardent Student of the Art of Wireless Teleg- 
raphy. 



The normal sending range is 50 miles. 
Altho 1 have not a license, I receive sta- 
tions as far as Key West (1,200 miles dis- 
tant). My call is 1HR. 

I have also increased the efficiency of my 
station by adding an Oscilaudion bulb, a 
new rotary gap and an oscillation trans- 
former. 

PAUL RALSTON. 
Conneaut Lake, Pa. 

550 WIRELESS MEN AVAILABLE 
IN PHILADELPHIA. 

A trained body of 300 expert wireless 
operators now working on ships at sea or 
at commercial or naval stations along the 
coast, and 250 amateurs capable of com- 



The Waco, Texas, High School Radio 
Club. 

In September, 1914, the Waco High School 
Radio Club was organized with a charter member - 
ship of four. 

To-day the club has an active membership of 
thirty, a first-class one kilowatt transmitting set, 
two receiving sets (one an ordinary 4,000 meter 
Audion set and the other a 2,500 meter regen- 
erative set), hot wire ammeter, wave meter, motor- 
generator set, Multi-Audifone set, Omnigraph and 
various other experimental apparatus. 

The Radio call is 5 YG. The club meetings 
are held every Friday evening. The club would 
welcome all communications sent to Willis F. 
McCracken, care of Waco High School Radio 
Club, Waco High School, Waco, Texas. 

Ypsilanti Radio Amateur News. 

The Ypsilanti Radio Amateurs have elected the 
following officers for the coming year: — President, 
Donald Knight; Secretary. Allen Rust; Treasurer, 
James Orr; Sergeant-at-Arms, Louis Roberts. 

The club participated in a local exhibit' during 
America's Electrical Week. 

School Forms Radio Club at Arlington, 
Mass. 

A wireless club was formed by the pupils of 
the Russell Grammar School of Arlington, Mass., 
during the month of November. 

The following officers were elected: — President, 
Ernest A. Snow, Jr.; Vice-President, Richard 
Noyes: Secretary -Treasurer, Borden Billings. 

The club has a set installed and meets Tues- 
days and Thursdays in the afternoon to study the 
code. 



Dansville Wireless Association of 
Dansville, N. Y. 

On December 28, 1916, a number of "live wire 
radio amateurs organized the Dansville Wireless 
Association. 

The Club has twelve members and the station 
is located within the school building and would 
like to get in touch with other active clubs and 
amateurs. 

The officers of the club are James Welch, Presi- 
dent: Nobert Smith, Secretary and Conway J. 
Sheerin. Chief Operator. 



Uper Sandusky, Ohio, Wireless Club. 

The amateurs of LTpper Sandusky, Ohio, have or- 
ganized a club and have located in the business 



pleting their radio studies within a few 
months, is Philadelphia's contribution to 
the nation in the important branch of wire- 
less communication in event of war. In 
addition, forty students are now enrolled 
in the Philadelphia School of Wireless 
Operating. 

This school was the first to be estab- 
lished in America. It was started with a 
few pupils back in 1911, and since that 
time has turned out more than 300 trained 
men, nearly all of whom are holding com- 
mercial licenses to-day. 

All licenses for wireless operating are 
issued by the federal authorities, so that 
the records at Washington constitute an 
index of the operating force of the coun- 
try. In this respect Philadelphia is said 
to lead every other city with its 250 ama- 
teurs. 

Altho the operation of wireless stations 
is kept under government regulation, no 
order has been issued since the breaking 
off of relations with Germany to make 
regulations more drastic, and none is ex- 
pected. In some respects the large num- 
ber of amateur stations means better pro- 
tection for the city, for there is hardly one 
hour out of the twenty-four when some 
stations are not operating or listening. 

In addition to this force, Philadelphia 
is guarded by three powerful stations, 
Wanamaker's, League Island and Cape 
May. Most of the commercial business of 
the city is handled over the plant on the 
roof of the Wanamaker store. This is 
rated at 10Q miles, but its messages have 
been picked up as far south as Florida. 
The plant is generally closed now at night, 
but should the need arise it could be kept 
in constant operation and could pick up 
messages from a considerable distance out 
in the Atlantic. 



Amateur News 

section ot the town. The society consists of seven- 
teen members. We are installing a 1 K. W. trans- 
former and expect to install an Audion set in the 
near future. 

The following officers were elected on December 
1, 1916: Ralph Casey, President; Robert Maskey, 
Vice-president; Russel Selligman, Secretary and 
Hillis Berkey, Treasurer. 

Radio Amateur League. 

The Radio-Amateur League of Grand Prairie 
and Dalworth Park, Texas, was organized March 
5, and the following officers were elected: Frank 
M. Stubbs, President; Arthur Bradshaw, Vice- 
president; Ivan Ferguson, Secretary and Treas- 
urer; Joe Ward Edwards, Chief Radio-Engineer 
and Press Reporter. 

The "League" intends to construct most of its 
own instruments. We wish to communicate with 
other clubs and learn of their ideas. We have 
several ideas on the "Erection of Aerials" and 
the construction of other instruments which we 
will communicate to any clubs desiring this idea. 

All communications may be addrest to the secre- 
tary at Dalworth Park, and to the President, or 
Radio-Engineer, at Grand Prairie, Texas. 



Fifth District Radio Club Elects 
New Officers. 

In compliance with the by-laws of the club, Mr. 
R. B. Godbold was re-elected President; Karl Frueb- 
ing. Secretary -Treasurer and George Deiler, Li- 
brarian, who will serve the club until July, 1917. 

pllIlllllDllII 

1 RADIO CLUBS ATTENTION! j 



J We are always pleased to hear ( 

j from young Edisons and Radio ; 

jj Clubs. Send a write-up of your J 

J Club with photos of members and ■ 

J apparatus to-day to: Editor "Ama- J 

1 teur News" Section, The Electri- J 

1 cal Experimenter, 233 Fulton St., ] 

1 New York City. 1 



GIVE COLLEGE RADIO OUTFIT. 

bt. Ignatius s college of Cleveland, O., 
was presented with a new wireless outfit at 
an alumni smoker in the college gymnasium 
on February twentieth. The outfit was the 
gift of the alumni of the institution. Dr. 
Charles S. Howe, president of Case School 
of Applied Science, delivered an address. 

HARRY WALLE'S AMATEUR 
RADIO STATION. 

I present herewith a photograph of my 
wireless station, to be entered in your 
"Amateur Radio Station Contest." My set 
employs a 4 wire aerial 60 feet long. 
The receiving apparatus comprises a loose 
coupler, variometer, variable condenser, 
fixt condenser and a 50 tap tuning coil, 
which are all mounted complete in an oak- 
finished cabinet. The receivers are Trans- 
Atlantic 2,800 ohm type. The sending out- 
fit includes a 1-inch spark coil, helix, spark 




Harry Walle Finds Keen Enjoyment in His 
Small But Efficient Radio Station. 



gap and a key. I hear 8 U E, 8 R Y and 
8 G L very clearly. 

HARRY VANDE WALLE. 
Cincinnati, Ohio. 



The Headquarters of the Club are in the rooms of 
the Y. M. C. A. Radio School. The club owns a 
moderate library and has the use of a fine receiv- 
ing station, also a storage battery charging plant. 

Invitations are extended to all interested in the 
Radio Art. Meetings are held every Saturday 
night. Photographs of the club's set will be 
mailed upon request. We would also like some 
pictures from other clubs. Address all communi- 
cations to Karl Fruebing, 1232 Magazine Street, 
New Orleans, La. 



Eureka, Illinois, Radio Amateur News. 

On the evening of March 7, the Eureka Radio 
Club was formed and ten members admitted. The 
following officers were elected: Alvin Spencer, 
President; Glenn Dorward, Vice-president and 
Henry Klaus, Secretary-Treasurer. 

All communications should be addrest to the 
Secretary-Treasurer. 



Y. M. C. A. Radio Club of Springfield, 
Ohio. 

Under the leadership of Mr. E. Hineline, the 
amateurs of Springfield, Ohio, recently organized 
a radio club, which promises to be one of the 
most successful organizations of that locality. 
Widespread publicity was given in the local news- 
papers and it is reported that there are a large 
number of men and boys who are taking interest 
in wireless telegraphy. They have erected aerials 
and provided instruments, but so far have been 
working at cross-purposes with few people to talk 
to and no organization to further the work, so 
there is a need for a progressive club of amateurs. 

The members of the club have planned a sending 
set, capable of sending two hundred miles, and a 
long-distance receiving set to receive all high- 
powered stations in this country and Europe. In 
organizing the club, Springfield becomes a center 
of activity for amateur wireless. One of the prin- 
cipal objects of the Club will be to teach its mem- 
bers the use of the Continental Code and Mr. 
Hineline hopes to interest the Y. M. C. A. in 
the new club and in this way induce a large 
number of boys to participate. The temporary 
organization which was effected at the second meet- 
ing placed the following officers — Harold Stead- 
man, President; J. W. Fenton, Vice-president; 
E. J. Grieb. Secretary; Mr. Baldridge, Treasurer 
and J. W. Wright, Assistant Treasurer. 

Address all communications to the Secretary, 
121 Rose St., Springfield, Ohio. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



47 



EXPERIMENTAL PHYSICS. 

(Continued from \page 2$) 
a pointer which moves around and points 
to a circular scale which has been cali- 
brated to read the same as the ordinary 
mercury barometer. 
EXPERIMENT 23— 

A thin bottle (preferably a Florence 
flask) is tightly corked with a rubber stop- 
per, thru which a thin glass tube is con- 
nected. If this is inverted into a glass 
containing water to which a few drops of 
red ink have been added and the bottle is 
now heated, gently the air in the bottle 
will expand and some will pass into the 
water (see Fig. 19). If now the bottle is 
allowed to cool, some of the liquid will 
rise in the tube. If the colored water rises 
above half way up the tube some of it can 
be let out by raising the tube above the 
level of the water in the glass. This ap- 
paratus can now be used as a crude ther- 
mometer for obviously if heat is applied 
to the bottle, the air in the bottle will ex- 
pand and push the water in the tube back 
towards the glass; if a colder tempera- 
ture is applied the reverse will happen and 
the water will rise in the tube. The hot- 
ter the temperature the lower the level 
in the tube and the colder the temperature 
the higher the level in the tube. This ex- 
periment was first performed by the great 
Galileo and was the first method of meas- 
uring temperatures. 
EXPERIMENT 24— 

If a little ice is gradually added to some 
water in a highly polished vessel (a piece 
of the family silverware just answers the 
purpose) while the water is being stirred 
and a thermometer is kept in it, a tempera- 
ture will be reached when the polished sur- 
face fogs, i.e., (moisture forms on it). 
This temperature varies according to con- 
ditions of the atmosphere and is called the 
c';wpoint. This moisture does not leak 
thru the vessel as is commonly supposed 
but condenses from the atmosphere. We 
are all familiar with this phenomenon, hav- 
ing observed it every summer whenever 
ice water is served. The explanation is 
as follows — moisture is continually evap- 
orating into the atmosphere and when the 
atmosphere contains as much moisture as 
it can hold, it is said to be saturated. The 
same amount of air can hold more and 
more moisture as the temperature is in- 



creased and vice versa. Hence if the at- 
mosphere is saturated and the temperature 
is decreased, some of the moisture will 
have to condense as the atmosphere cannot 
hold more moisture than as much as it can 
hold. Likewise if the atmosphere is not 
saturated cooling it will saturate it and 
further cooling will cause moisture to 
condense. 

The cooling of the grass, trees, stones, 
etc., at night more rapidly than the atmos- 
phere itself cools, causes the formation 
of dew (a condensation from the atmos- 
phere). If the air near the earth also 
cools, the condensation also takes place on 
the dust particles near the earth and this 
condensation is called a fog. If this fog 
forms at some distance above the surface 
of the earth, it is called a cloud. If a 
considerable amount of moisture condenses 
in the cloud the drops become large and 
because of their weight fall as rain. Rain 
passing thru cold regions freezes into hail. 
If the temperature of condensation is be- 
low freezing the moisture condenses into 
crystals called snowflakes. 

( To be continued ) 



Amateur Radio Stations Licensed by the Bureau of Navigation During 
the Month of September, 1916 (Concluded) 



FIRST DISTRICT 



Call 
Signal 



8DE 
8OF 

8KE 

8AMX 

8BG 

8OC 

8RF 

8PH 

8HX 

8AMC 

9AJW 

9AIL 

9GH 

9AKB 

9AJT 

9AJR 

9AKF 

9AKG 

9AKJ 

9AJO 

9A.IS 

9VD 

9AKA 

9AKF. 

9AKH 

9AKD 

9HG 

9AKC 

9VQ 

9A.IU 

9AKK 

9AKT 

9AKL 



Owner of station 



Frost, Norbert . . . 
Hewitt, C. Tefft. 



Houk, Robert J 

Moyer, Edward A 

Peacock, Howard 

Simons, Harold C 

Slape, Frank 

Thomas, William K. . . . 

Towsley, Paul W 

Warden, William F., Jr. 



Baer, Elwynn W 

Becker, Alby 

Branom, Albert L 

Davis, Laurence O. . . . 

Dubuque College 

Fox, Harry 

GitchofT, Anton A 

Hamlett, Robert T. . . . 
Hammond, George R. 

Hardy, Reginald 

Herr, Carl E 

Herron, Carson L. . . . 
Holmberg, Harry E. . . 

Keller, Warren H 

McBride, Kenneth. . . 

Markley, Max 

Nelson, Earl P 

Niessen, Leonard P. . 

Poser, Stanley F 

Robinson, Roy E 

Eyder, Earl 

Tuhtar, Eugene W.. . 
Werlein, Edwin 



Location of station 



552 Glenwood Ave., Buffalo, N. Y. 
7942 Westmoreland Ave., Swiss- 

73 Douglas St.',' Tiffin,' Ohio'. '. 

640 N. Sandusky St., Bellevue.Ohio 

Barker, N. Y 

617 May St., Lansing, Mich 

106 Eureka St., Pittsburgh, Pa. . . 
400 Minton St., Pittsburgh, Pa. . . . 
1019 Bement St., Lansing, Mich.. . 
R. F. D. No. 11, Cuyahoga Falls, O. 

NINTH DISTRICT 

... 1710 4th St., Madison, 111 

... 3146 32d St., Catlettsburg, Ky 

. . . 208 Giddings Ave., Jerseyville, 111. 

. . . Hazard, Ky 

. . . Dubuque, Iowa 

... 3116 N. 24th St., Omaha, Neb 

. . . 500 5th St., Madison, 111 

. . . Fulton, Ky 

. . . . 219 S. 5th Ave., Selwein, Iowa. . . . 

441 49th Ave., West Allis, Wis. . . . 

540 9th St., Red Wing, Minn 

. . . . 1712 Court St., Le Mars, Iowa. . . . 

. . . . Bottineau, N. D 

. . . . 101 Lincolnway, La Porte, Ind 

. . . . 101 Bowen Ave., Independence, Mo. 
. . . . 416 W. Central Ave., Bluffton, Ind. 
. . . . 1320 Commercial St., Waterloo, la. 
. . . . 430 Layton Blvd., Milwaukee.Wis. 

730 1st St., Milwaukee, Wis 

. . . . 3257 Alcott St., Denver, Colo 

806 S. College St., Springfield, 111. . 

503 6th St., Milwaukee, Wis. , 

. . . . 4060 Lincoln Ave., Chicago, 111 



A ONE-MAN ELECTRIC 
SUBMARINE. 

(Continued from page 6) 
on ) to make several short, quick trial 
maneuvers, until he bumps into the hull of 
the enemy vessel. Also he can see a dis- 
tance of 25 to 50 feet or more under water 
by means of the powerful electric search- 
light, and once against the hull of the ene- 
my Submarine or Dreadnought, it is but the 
work of a moment to excite the electro- 
magnets in the war-head which instantly 
grip the steel plates of the enemy vessel 
with a powerful hold, and to release the 
war-head by means of the electro-mag- 
netic clutches previously mentioned. The 
operator then scurries away at a mile-a- 
minute speed, and if he is but one quarter 
of even one-eighth of a mile away when 
the war-head explodes, he will be safe. 
In the event that the comprest air and gas- 
oline engine driving machines should both 
fail on his return trip, he can send out 
distress rockets thru the rocket shute at- 
tacht to the periscope column, and thus 
be rescued by a boat from the mother-ship 
or by patrol boats sent out from shore. 

MAGNETIC IN- 
DICATOR FOR 
CRITICAL TEM- 
PERATURES. 

The fact that 
steel loses its mag- 
netic properties on 
attaining the criti- 
cal temperature 
forms the basis on 
which has been de- 
signed an instru- 
ment which infall- 
ibly indicates the in- 
stant when a mass 
of steel has attained 
the decalescent or 
hardening point. 
The instrument 
consists of a con- 
tact box contain- 
ing magnet and 
coils, mounted on 
one end of a rod 
provided with han- 
dles and heat shield. 
The other end of the 
rod carries a flux- 
meter, the needle of 
which indicates the 
gradual approach of 
the steel to the non- 
magnetic or critical 
point. 



Power 
kilowatt 



THE THERAPY OF LIGHT AND 
THE NEW "R-RAY." 

(Continued from page 15) 

radiation is somewhat similar to the Ultra- 
violet ray, inasmuch as an arc is used ; 
but two different arc electrodes are em- 
ployed in this work. The arc is produced 
between an electrode composed of quartz 
and mercury with a second electrode of 
ordinary arc carbon. Fig. 1 shows one 
of the complete arc lamps used in these 
experiments. 

Viewed as a soectrogram the R-ray oc- 
cupies one side of the Ultra-violet region, 
and grades uniformly from the first octave 
to out and beyond the visible portion. Al- 
so here we find radiations that cause air 
and matter to have such affinity that they 
are instantly absorbed, and investigation 
of their characteristics can only be con- 
ducted in a vacuum. 

As resultant deductions of therapeutic 
interest in considering the properties of the 
R-ray, we find the following: 

(1) They are readily controllable and 
give penetrative therapeutic light of unin- 
terrupted intensity. 

(2) They are rich in Ultra-violet rays 
of shorter wave lengths than the emissions 
from any other known arc. 

(3) They differ materially from X-rays 
in that they may be deflected and focussed 
on any given area, so as to combine their 
inherent heat-ray value with their visible 
and invisible light radiations. 

(4) They are more readily absorbed by 
matter than any present known arc ray, 
and as such secure vibratory reactions in 
deep-seated cellular organisms. 

In order to show the position of the un- 
mapt region wherein the R-ray lies, and as 
compared with the vibrations of other 
sources of radiation, the chart, Fig. 2 was 
made. It will be found very interesting to 
those who are pursuing the study of differ- 
ent sources of radiations. 

The chart indicates the wave lengths of 
radiations ranging from the visible part of 
the spectrum to X-rays and the Gamma 
rays of radium. 

To fully understand this chart, the fol- 
lowing notation is used : the numbers across 
the top give their respective wave lengths 
in Angstrom units (one Angstrom unit is 
equal to 1/10 of a meter and this unit is 
abbreviated as A.U.). Thus the waye 
lengths are given in tenths of a meter, 
using here the language of the scientist. 
The Angstrom unit is equivalent actually 
to 10 10 meter, one meter being equal to 
39.37 inches. The numbers below represent 
the number of octaves which these rays 
range over. 

The region of about six octaves, begin- 
ning at 4 and ending at 10, represents the 
unmapt portion. This separates the ex- 
treme ultra-violet from the commencement 
of the very soft X-rays. The most easily 
absorbed X-rays, whose wave length has 
been determined, are the characteristic rays 
of burning aluminum with a wave length of 
8.4 A.U. Passing up thru several octaves 
of X-rays, the limit indicated by the line 
"N" is reached; these represent the hardest 
i.e., the most penetrating X-rays, which 
have so far been produced. The line "M" 
represents the medium penetrating ray. It 
will be noticed that some of the gamma 
rays as produced by the disintegration of 
the radium atom, are of longer wave 
lengths than some of the shorter X-rays. 

The region ranging between octaves 4 
and 10 are vibrations which are easily ab- 
sorbed by matter. They vary in wave 
length from approximately 900 to 9 A.U. 
The region between wave lengths 3,800 to 
1,900 is the portion of radiation which is 
of therapeutic interest. 



THE ELECTRICAL EXPERIMENTER 




May, 1917 



PATENTS 



Magnetic Drilling Attachment 

(No. 1,219,190; issued to Henry 
Symes.) 

The inventor here provides an 
electro-magnetic means of feeding 
a machine drill against its work. 




An iron frame supports the drill 
spindle, which is driven by an elec- 
tric motor. The spindle carries a 
suitable iron yoke and pole-pieces 
which are acted upon attractively 
by powerful solenoid electro-mag- 
nets, tending to pull the iron pole- 
pieces within in the coils. The cur- 
rent supplied the magnet coils can 
be varied to give various degrees of 
pull on the drill frame. For long 
vertical action two or more sets of 
solenoids, one above the other, can 
be utilized as shown. 



Electric Phonograph Recorder 
and Reproducer 

(No. 1,218,799; issued to Herman 
G. Pape.) 
A device for making phonograph 




records and combining in its make- 
up a suitable electro-magnet, a dia- 
fram, and a means for causing the 
diafram to vibrate in response to 
electrical impulses in the electro- 
magnet — as from a microphone. 
Acoustic vibrations or sounds can 
operate the diafram as usual thru 
an open grid above it, a stylus being 
connected to the diafram to vibrate 
with it. 

Electric Voting Machine 

(No. 1,219,053; issued to Marshall 
F. Thompson and Arthur L. 
Townsend.) 



fl£V TT <T 
t=>o e 




G30 O O 
DO O • 


CZZ30 
C=3 O O O 




a=30 




6»TTt«Y 
0UTT0H 0M Qf 



An electrically operated voting 
board which includes provision for 
totaling and recording all of the 
votes cast and flashing them up on 



an indicator board The primary cir- 
cuit includes a voter's circuit closer, 
a visual lamp signal and a relay 
magnet. The latter closes a secon- 
dary circuit including the visual sig- 
nal and a vote recording mechan- 
ism. Also there is provided a spe- 
cial circuit breaking attachment out 
of control of the voter, for the pur- 
pose of breaking the primary or 
voter's circuit. The idea is par- 
ticularly applicable to government 
and society meeting chambers, mak- 
ing it possible to record and an- 
nounce the vote of members present 
in the minimum of time. 



Magnetic Speedometer 
(No. 1,219,245; issued to Allen A. 
Canton.) 




A radical departure in speed- 
ometer design, involving the use of 
a permanent steel magnet of ring 
form, over which are placed two 
movable magnet windings, one of 
which is supplied with a constant 
electric current and means for in- 
termittently supplying electric cur- 
rent to the second solenoid coil. 
The magnetic reaction occurring 
with such an arrangement causes 
the coils to move. In so doing they 
rotate a geared sector, as shown, 
the sector teeth meshing with a 
small gear pinion fixt rigidly to the 
dial shaft, thus causing the num- 
bered dial to move under an obser- 
vation slot or window. 

High Frequency Oscillation Appar- 
atus 

(No. 1,216,646; issued to James C. 
Armor.) 




A novel scheme for producing 
high frequency oscillations for ra- 
dio-telegraphy, radio-telephony and 
similar arts. Using alternating or 
direct current as a source, the in- 
ventor provides choke coils 8 and 
resistances 7, across which is shunt- 
ed the special spark gap 4-4. This 
gap is shunted by an oscillatory cir- 
cuit comprising suitable condenser 9 
and inductance 10. The first dis- 
charge wave of the condenser across 
the gap is quenched by blowing a 
high velocity (5,000 ft. per second) 



jet of gas or fluid between the rapid- 
ly rotating spark discs 4, 4. Higher 
efficiency is claimed and the pro- 
duction of extremely high fre- 
quency, dead-beat unidirectional dis- 
charges. 



Hearing Device 




(No. 1,219,411; issued to Charles 
E. Williams.) 
A specially sensitive electric tele- 
phone device to aid partially deaf 
people to hear better. Operating on 
the dictograph principle it com- 
prises a super-sensitive microphone 
which is connected with a suitable 
telephone receiver and a high volt- 
age battery. The battery comprises 
a plurality of cells and means for 
reducing the high potential by hav- 
ing an extra resistance wire between 
a terminal on one cell and a pole 
of another, with flexible connec- 
tions between the external terminals 
to the receiver and microphone. 

Radio Transmitting System 




(No. 1,216,615; issued to George 
Seibt.) 

A radio transmitter operating on 
direct current, which is supplied to 
a quenched gap, thru suitable choke 
impedances and resistances. A 
suitable coupling is provided to en- 
able the cutting off of oscillations 
in the closed primary oscillating cir- 
cuit after the first beat of the os- 
cillations. The spark gap is de- 
signed to be short, and a rapid heat 
dissipater, thus quenching the spark 
and giving rise to powerful, slowly 
damped free oscillations in the 
secondary or aerial-ground oscillat- 
ing circuit and, it is claimed, that 
the two-coupled oscillations practi- 
cally disappear. This system is 
adapted to radio-telephony, using a 
microphone in the ground lead. 



Submarine. Subterranean and 
Aerial Telephony 

(No. 1,212,202; issued to Reginald 
A. Fessenden.) 
A new phase of the Fessenden 




system of setting up, transmitting 
and receiving powerful sound waves 
in the form of telegraphic and tele- 
phonic signals thru water, land or 
air. Prof. Fessenden here invokes 



the use of the Alexanderson mag- 
netic amplifier 11-13, with which to 
control by microphones, the output 
of say a 100 K.W. radio frequency 
alternator. This R F. current is past 
(also modulated by secondary 11) 
thru a rectifier 17, thence into a 
non-inductive oscillator 20. This is 
linked up with a metallic beam gir- 
der 23, supported at two points, as 
shown, and carrying a large metal 
diafram 26, say 50 feet square. 



Precision Variable Inductance 

(No. 1,217,348; issued to O. F. 
Rothen.) 

The smallest part of a turn of the 




spiral may be accurately tuned in 
or out of the circuit by simply turn- 
ing the central knob or handle. 
Spiral inductances of this type in- 
variably have the defect that the 
slider will not follow the turns. 
Here the inventor provides a toothed 
rack on the slider arm which co-acts 
on a fixt central gear stud, so that 
as the handle is turned the slider 
arm is moved in or out accordingly 
and in a spiral path the complement 
of the helix. The pitch circum- 
ference of the stationary pinion is 
selected equal to the radial pitch 
of the spiral. 



Electric Musical Instruments 

(No. 1,216,829; issued to Harry S. 
Martin.) 

When an interrupted current of 
the frequency corresponding to any 
certain musical note is fed into 




COPIES OF ANY OF THE ABOVE PATENTS SUPPLIED AT 10c EACH 



electro-magnet 16, it causes pulsat- 
ing magnetic forces to act on the 
tuned reed 13. This in turn sets 
the diafram 1 1 vibrating at a cor- 
responding periodicity, which vibra- 
tions are communicated to the col- 
umn of air in horn 1, thru the an- 
nular mouth 3. Diafram 11 carries 
a felt ring 22, which may be dis- 
pensed with for certain effects. By 
this means it is claimed that ex- 
tremely powerful and unusual son- 
orous vibrations are set up. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



49 



PHONEY PATENT OFFIZZ 



Jq.r 

No.\te 



M. 



Q.S.B. 



>Q.S.C. 



To Whom It Should Worry: 

Let it be knowed to all fathers, fatheads, 
mothers, parents, and elders thruout the 
land and the seven seas and lakes, that I, 
Constantine Ulysses Spidor of the City of 
Peramblator, in the state of prolonged 
coma, have imagined, conceived, designed 
and executed, at the risk of my imperfect 
sanity, an apparatus which will revolution- 
ize the baby industry and do away forever 
with "the hand that rocks the cradle." 

It is a greatly to be lamented fact that 
our national baby industry has suffered 
greatly during the past decade, primarily 
for the reason that babies, infants, brats 
and other similar nuisances tend to keep 
their elders at home and away from tango 
parlors and the "movies." Not that the 
parents cherish the idea of staying in, no, 
not that. They hafto. For, if the nurse or 
hired girl take their daily spin in the fam- 
ily "Tin-lizzie," who would feed the brat 
to still his or her war-whooping? 



AUTOMATTICK BRAT HUSHER 
C. U. SPIDOR OF PERAMBLATOR, CA. 

Species Fikation of Patent Lettors 

may now tango or "movie" all night, if 
so desired, without in the least retarding 
the natural growth of their offspring. Also 
and most important of all, "Pah-pah" need 
no longer invent new forms of sudden 
strokes, cramps, colds, fevers, chills, etc., 
which make it impossible for him "just 
then" to leave a comfortable, warm bed, in 
order to perform the twice-nightly Mara- 
thon with an obstreperous brat, clutched 
. tightly in his arms. 

Having thus explained my invention in 
non-technical terms, I now refer to the pat- 
ent drawing for further elucidation: 

1, is a sensitive (but happily unfeeling) 
microfone. The first brat-yell jars its sen- 
sibility to such an extent that current be- 
gins to flow thru it at a terrific rate, which 
in turn operates electromagnet 2. This ac- 
tuates pawl 3 permitting Thermos-bottle 4, 
containing the best imported Extract de 
Cow to con-descent downward into the 
brat's fists. Instinctly the Brat stuffs the 



Patent Buscated 

not satisfied with cow-juice and perambu- 
lating joy rides only. They wish to be 
talked to and sung to. Bearing this re- 
quirement in mind, when bottle 4 is empty 
and has ascended once more, thanks to 
coil-spring 13, electromagnet 12 releases 
victrola which begins to talk and sing lul- 
laby to brat. This so bores the latter that 
he, she or it, falls to sleep at once. 

If, perchance, the Brat should wake up 
once more and yell, 10 gets busy once more 
and perambuscates at once. Spring 14 has 
reset reproducer 15 in the meanwhile, when 
mother's original selection issues forth 
anew. This so disgusts the Brat that he, 
she or it, falls to sleep instanter. 
What I claim, is: 

1° A self-contained automattick Brat- 
husher. 

2° A Brathusher making attending par- 
ents and nurses unnecessary. 

3° A Brathusher supplying feed, lullabys 
and rocking simultaneously. 




Let it Be Knowed to All Fathers, Fatheads, Mothers, Parents, and Elders thruout the Land and the Seven Seas and Lakes, that I Constan- 
tine Ulysses Spidor of the City of Peramblator, in the State of Prolonged Coma, Have Imagined, Conceived, Designed and Excuted, at the 
Risk of my Imperfect Sanity, an Apparatus Known Hereinafter as an "Automattick Brat Husher" Which Will Revolutionize the Baby In- 
dustry and Do Away Forever with "the Hand That Rocks the Cradle." 



The sad result of the upshot is, that the 
annual total production of babies and brats 
has almost reache 1 the vanishing point. It 
is also to be noted with significant signifi- 
cance, that altho everything else imagin- 
able has gone up during the war, only the 
output of babies and brats has gone down ! 
And this despite of the constant uproar- 
ous roar of Teddy from Oyster Bay. 

Happily, such disgraceful conditions need 
prevail no longer, due principally and solely 
to my marvelous Automattick Brat Husher. 
By using this inexpensive apparatus, parents 



nipple in its empty void and the land be- 
comes quiet once more. But this is not the 
end of a perfect day. Simultaneously 
with the descent of bottle 4, a contact is 
made and electromagnet 5 attracts switch 
6, usually held off by spring 7, which now 
actuates instinctanously motor 8. Gear 9 
takes up the Q.S.T. (General Call) and 
Perambulator 10 now begins to perambus- 
cate viciously back and forward, being 
thus induced by arm 11. 

Neither does this end the story. Brats 
as a rule, due to the cunning of nature are 



In subscribing to the above facts, I have 
therefore implanted my own facsimile oto- 
graf hereunder and forever on this 27th 
day of Monday in the 53rd year after the 
advent of the safety-pin. 

C. U. SPIDOR. 

By his Attorney 
A. Bruce Brown, 
Norwich, Conn. 
Witnoses: 
S. H. Utup 
Wade U. Givenus 
Fore F. Lusher 



So 



THE ELECTRICAL EXPERIMENTER 



May, 1917 





QUESTION BOX 



This department is for the sole benefit of all electrical experimenters. Questions will be answered here for the benefit of all, but only matter of sufficient interest 
will be publisht. Rules under which questions will be answered: 

1. Only three questions can be submitted to be answered. 

2. Only one side of sheet to be written on; matter must be typewritten or else written in ink, no penciled matter considered. 

3. Sketches, diagrams, etc., must be on separate sheets. Questions addrest to this department cannot be answered by mail free of charge. 

4. If a quick answer is desired by mail, a nominal charge of 25 cents is made for each question. If the questions entail considerable research work or intricate 
calculations a special rate will be charged. Correspondents will be informed as to the fee before such questions are answered. 



RADIO QUERIES. 

(760.) Harold Janeway, Edmonds, 
Wash., asks : 

Q. 1. Could I hear amateur stations with 
a loose coupler, galena detector, fixt con- 
denser, and an Electro "Government" 
'phone in connection with an aerial fifty 
feet high and thirty feet long? If not what 
other instruments would I need? • 

A. 1. There is no reason why you should 
not receive amateur stations with the in- 
struments you mention. A variable con- 
denser shunted across the secondary of 
your loose coupler will increase the selec- 
tivity very much. 

Q. 2. How can I drill holes in a marble 
slab so that I can mount a ground switch 
upon it? 

A. 2. An ordinary steel twist drill should 
be employed which should be constantly 
kept wet by applying water to its boring 
surface. 

Q. 3. Would I be violating the rules of 
the Fire Underwriters if I put a box over 
my outside ground switch and covered the 
ground wire with lath? 

A. 3. Yes. The ground wire should be 
kept free from any surrounding objects. 

POWER FROM PRIVATE PLANT. 

(760-A.) W. C. Guibb, Grabill, Ind., 
wishes to know : 

Q. 1. What is the best way to use the out- 
put of a private lighting system in a radio 
sending set? The generator has an out- 
put o-f 30 to 45 volts and 13.3 amperes, and 
charges a storage battery of 16 cells. 

A. 1. The best way to utilize the electric 
power generated by your private plant is 
to employ a spark coil outfit; the size of 
the coil will depend upon the distance 
which you desire to cover. 

Q. 2. Can I use it in connection with an 
open or closed core transformer, or is the 
spark coil the only way? 

A. 2. Yes, providing that a mechanical 
vibrator is used in conjunction with it when 
using an open core transformer. This can 
either be directly operated by the transfor- 
mer core or else you may employ an inde- 
pendent vibrator. We would advise that 
you employ a spark coil, say about a 4- 
inch coil, and you will find that it will give 
better service than if an open core trans- 
former is used. 

Q. 3. Could I not use the combined 
voltage of the generator and battery and 
have sufficient voltage? 

A. 3. Yes ; but the voltage will not be 
sufficient or of the correct character to op- 
erate a transformer without a mechanical 
interrupter. 

UNDAMPED WAVE RECEPTION. 

(761.) Walter B. Clifford, Worcester, 
Mass., writes: 

Q. 1. Is it possible to employ a mineral 
detector in place of an Audion detector 
for receiving undamped signals? If so, 
what connection of instruments should be 
used? 

A. 1. It is possible to receive undamped 
waves by employing a crystal detector pro- 
viding a tikker of some kind is employed 
in the detector circuit. The diagram of 



connections is given herewith and shows a 
circuit breaker or tikker being used. 

Q. 2. Will you please publish a diagram 
of the connection of the instruments used 
in a simple inductive wireless telephone 
circuit ? 

A. 2. Our diagram gives the connection 
of a simple radio telephone employing the 
induction principle. The transmitting coil 
should be five feet in diameter while the 
receiving coil is four feet. Each coil is 
wound with one hundred turns of annun- 
ciator wire. 

Q. 3. Is it advisable to employ a helix 
with a one inch spark coil? 

A. 3. If you desire to bring your trans- 
mitting wave length to some definite value, 
you should employ a helix. 




V.C. Cdntfcts 



TifAerl o 



0*76, 



Proper Connection for "Tikker" Type of 
Radio Receiving Circuit for Undamped Wave 
Signals. 



Transmuting Coii 
Receiving Coil vmsmmf 



Telephone 





induction Coil 




Hook-up for Inductive Wireless 'Phone. 



SELENIUM. 

(762.) E. W. Donaldson, Fairmont, W. 
Va., wishes to know : 

Q. 1. In what quantities is the element 
selenium available? 

A. 1. This element can be supplied to 
you in any quantities desired, and it may 
be procured from The Electro Importing 
Co., Kew York, N.Y., or Electro-Set Co., 
of Cleveland, Ohio. 

Q. 2. Does it remain constant in its 
conductivity under periods of use, say 
three or four seconds several times a day 
or longer? 

A. 2. The conductivity of selenium crys- 
tals under the influence of light is not con- 
stant but variable. The variation of con- 
ductivity of lenium depends upon many 
factors, such as the applied voltage, source 
and intensity of illumination and chemical 
purity of the selenium crystal. 



MOTOR STARTING QUERY. 

(763.) J. Adler, New York, N.Y., asks: 
Q. 1. How should a shunt motor be 
started ? 

A. 1. First, the field current is applied 
at full line voltage; then the armature cur- 
rent is thrown on at much less than line 
voltage, the voltage being held down or 
controlled by resistance in a starting box; 
as the motor comes up to normal speed, re- 
sistance is cut out step by step until full 
line voltage is imprest on the armature. 
This is all accomplished by one motion of 
the handle of a well-designed rheostat or 
starting box. Most starting boxes are so 
arranged with a magnetic release or other- 
wise, that the motor is automatically cut 
out of the circuit in case the line voltage 
should, thru any accident, be shut off. 

Q. 2. What is an accumulatively wound 
compound motor? 

A. 2. It is a motor whose series and 
shunt field windings are in the same direc- 
tion and therefore as the load comes on 
the series field assists the shunt field and 
a stronger magnetization and increased 
torque, with slightly reduced speed, results. 

STORAGE BATTERIES. 

(764.) Harry Blumenthal, Harrison, 
N.J., wants to know : 

Q. 1. To what use is the storage bat- 
tery sometimes put in electric lighting or 
power stations? 

A. 1. To carry the peak of the load, i.e., 
that excessive portion of the load which, 
for instance, in electric lighting stations 
has to be carried only for two or three 
hours a day. They carry the entire load 
at minimum hours; to act as equalizers or 
reservoir. 

Q. 2. How do Faure plates compare with 
those of the Plante type? 

A. 2. They are usually lighter and have 
a higher capacity, but have a tendency to 
shed the material from the grid, thus ma- 
king the battery useless. 

Q. 3. At what density is the resistance 
of dilute sulfuric acid at a minimum? 

A. 3. At 1.260 Baume. 



MOTOR ACTION. 

(765.) L. Askel, Detroit, Mich., asks: 

Q. 1. Why does the speed of a shunt 
motor increase when the position of the 
brushes is off neutral? 

A. 1. When the brushes are shifted from 
the neutral plane, the reverse voltage be- 
tween the brushes is decreased, the speed 
remaining unchanged. Accordingly, the 
pressure in the supply mains forces an in- 
creased current thru the armature, thus 
producing an increased armature pull, 
which causes the speed to increase until 
the reverse voltage reaches a value suffi- 
ciently large to reduce the current to the 
value required to supply the necessary driv- 
ing torque. 

Q. 2. Can you tell me the existing mu- 
tual relations of motor torque and speed? 

A. 2. The character of the work to be 
done not only determines the condition of 
the motor torque and speed required, but 
also the suitability of a particular type of 
{Continued on page 52) 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



5i 




8c in 
Stamps 
Brings 
You 



DUCK'S 



300 -PAGE ELECTRICAL 
and WIRELESS CATALOG 

You then have everything in wireless and electrical supplies worthwhile at prices 
that mean a substantial saving to you. Our catalog is recognized by all experi- 
enced and advanced amateurs as the Beacon Light on what to buy. Ask your wire- 
less friends. Great cost of catalog and low prices prohibit distribution unless 
upon receipt of 8 cents, which you may deduct on first dollar purchase. 



SHORT WAVE REGENERATIVE SET 
Every worth while feature is incorporated in this Regenerative Set. Initial 
tests in our laboratory and at thelocal Scott High School brought in with re- 
markable clearness amateur stations in Texas, Louisiana, Wisconsin, and all 
eastern states, A mplification and selectivity surpassed several other sets tested 
in conjunction with it. We have no hesitancy in claiming for this instrument no 
superior, and in fact we thusfar know of none that equals it. It is designed for 
wave lengths from 180 to 475 meters. Caseb'j/'x I 1 ;t 4 " x 634". nand rubbed 
mahogany finish. Panel, polished Formica. Set has variable coupling. 

This is essential 
forselectivity and 
the elimination of 
static, the reby 
insuring greatest 
possible range. 
Primary circuit 
a d j u s table by 
single turns. 
Grid inductance 
adjustable by 1 2 
point switch. 
, Special variable 
condenser includ- 
1 ed in circuit for 
I close tuning. 



Type "C" Sayville Gap, Copper Elec- 
trodes, Rotary Wheel Bakelite 
SV 2 " dia. 




b '*. 5 ""mntiJ 



$24.75 
Prepaid. 



SOME STARTLING REDUCTIONS FOUND IN CATALOG NO. 11 
_ Reduced Price 

T-O Thordarson Flexible Transformer $12.25 

T-l " " " 16.25 

T-2 " " " 19.75 

Protective Device free with each transformer 



Undamped Loading Inductance 

Hear the Arc stations in Germany and 
elsewhere. 

No. 528 for secondary loading coil and 
tor tuning the wing circuit, $7.75 

No. 1526 for primary 
loading coil, $7.75 
Two No. 528 and one No. 
1526. $22.00 
None on the market 
equals these undamped 
loaders at $10.00 each. 
No. 22 & 28Silk Covered 
Wire is used on primary 
and secondary, respec- 
tively. Variation of in- 
ductance is by means of 
20 point instrument type 
switch mounted on 3^t" 
Bakelite. With an ordin- 
arily loose coupler wave 
length 15.000 meters. 

Reduced Price 

No. A 395. Oscilliation Transformer $13.50 

Model 5AA Navy Type Transformer 17.25 

No. 1091 Arlington Transformer 7.50 

No. 1092 " " 6.50 

Send 8c lor this Catalog today. You need it 



All electrodes are of 1 A ,f round copper. Re- 
volvingelectrodes 3 long. Stationary elec- 
trodes inch long. The use of copper for 
the electrodes and their unusual size makes 
thisgapmuch more efficient than any other 
gap of its type on the market. The copper 
conducts the heat away from the sparking 
surfaces. AH advanced radioengineerscon- 
cede that copper is unsurpassed for elec- 
trodes. Gap equipped with Universal 
motor. For use on stations up to 3 K.. W. 




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52 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



EXPERIMENTAL CHEMISTRY. 

(Continued from page 43) 
EXPERIMENT NO. 52 

Wash the test tubes, add fresh acid, and 
drop a piece of Calcium carbonat (marble) 
into each tube successively. Proceed in the 
same manner as with the metals in the 
foregoing experiment, only in this case the 
gas must be tested not only with a burning 
match, but as follows : Dip a clean glass 
rod into lime-water, and hold it in the 
escaping gas. (The escaping ^as is Carbon 
dioxid) . 

The results of these experiments are 
characteristic of all acids, and substances 
acting thus are said to be Acid, or to have 
Acid properties, or to have an Acid re- 
action. 

The test with litmus paper is true only 
for litmus, but it is a striking, simple test 
for acids, and should be remembered, that 
acids turn blue litmus red. 
BASES— 

Bases in chemistry, includes those Hy- 
droxids of metals which neutralize acids 
by partly or entirely replacing their hy- 
drogen, thereby yielding compounds called 
salts. 

Bases are in a few cases soluble, in most 
cases insoluble. When soluble in water 
they turn red litmus blue, and possess caus- 
tic properties. 

Bases usually have an acrid or bitter 
taste. 

Since every base contains Hydrogen and 
Oxygen they are sometimes called Hy- 
droxids. Hydrat is sometimes used as a 
synonym of Hydroxid, while the term Al- 
kali, emphasizes general properties rather 
than suggests specific composition. Hy- 
droxids are distinguished from each other 
by placing the name of the metal before 
the word Hydroxid, as, Sodium Hydroxid, 
Potassium Hydroxid. 

Not all bases contain the same number 
of hydroxyl groups. Therefore, bases, 
like acids, may form one or more salts. 
This power is called Acidity. Bases are 
called, Monacid, Diacid, Triacid bases, etc., 
according to the number of replaceable hy- 
droxyl groups present in the molecule. 
Calcium hydroxid (Ca[OH] 2 ) is a diacid 
base, and Aluminum hydroxid (Al[OH] 3 ) 
is a triacid base. 

A base contains a metallic element, as, 
Potassium (K), Sodium (Na), Copper 
(Cu), Calcium (Ca), Iron (Fe), Zinc (Zn), 
together with Hydrogen and Oxygen. 

Below are bases : 

Potassium Hvdroxid KOH 
Sodium Hydroxid Na[OH] 
Calcium Hydroxid Ca[OH] 2 
Ferric Hydroxid Fe [OH], 

Copper Hydroxid Cu [OH], 

Zinc Hydroxid Zn[OH] 2 
Ammonium Hydroxid NH 4 OH 
Aluminum Hydroxid Al[OH] 3 _ 
When a salt is formed from an acid 
and base, the metal of the base enters into 
the acid in place of the hydrogen, and the 
hydrogen combines with the Hydrogen and 
Oxygen of the base to form water (H 2 0). 

HNO3 + KOH = KNO3 + H2O 
Nitric acid Potassium Potassium Water 
Hvdroxid Nitrat 
(Acid) + "(Base) = (Salt) + (Water) 

The same is true of the following: 

H2SO4 + 2NaOH = Na 2 S0 4 + 2H2O 
Sulfuric acid Sodium Sodium Water 
Hydroxid Sulphat 

EXPERIMENT NO. 53 

Pour 5 CC. of Ammonium Hvdroxid 
(NH4OH), 5 cc. of Sodium Hydroxid 
(NaOH), 5 cc. of Potassium Hydroxid 
(KOH), into separate test tubes and place 
in a test tube rack. Add about 5 cc. of 
water to each, and shake the contents. 

Place a piece of both red and blue lit- 
mus paper (or litmus solution^ may be 
used, a drop being sufficient) into each 
tube and note the result. 



It will be noticed upon the introduction 
of the litmus, that the blue paper (or solu- 
tion) is unaffected, while the red paper (or 
solution) has turned blue. This is a char- 
acteristic of all bases, and is employed as 
a test for them. 

After testing as above pour the contents 
out and rinse the tubes. 

If we arrange the symbols of the above 
bases we have : 

NH4OH 
NaOH 
and 
KOH 

It will be noticed that the OH or hy- 
droxyl is contained in all three. It will 
also be noted that the remaining portion, 
namely, NH 4 , Na, and K, are metallic. 
That the bases turn red litmus blue. 
SALTS 

A salt is a substance composed of a met- 
al or positive radical united with a non- 
metal or negative radical. These com- 
pounds in some respects resemble common 
salt, that are formed by the replacement 
of the hydrogen of acids by metallic radi- 
cals, both simple and complex. They may 
be classified as Normal, Acid, and Basic 
salts, according to whether the hydrogen 
of the acid is completely or only partially 
replaced in the first two cases, or whether 
the Oxygen or hydroxyl groups of a base 
are only partially neutralized by an acid in 
the last. 

A salt generally has an acrid taste. 
Some salts are soluble, some insoluble. 
Salts may be prepared by one of the fol- 
lowing types. 

1. Action of a metal on an acid. This, 
besides forming the salt, usually sets free 
hydrogen or some decomposition product 
of the acid produced by its action. For 
example, Zinc sulphat and copper nitrat 
are produced by the reactions; 

Zn + H2SO4 = ZnS04 + H2 

Zinc Sulfuric Zinc Hydrogen 
Acid Sulphat 

and, 

3Cu + 8HNO3 = 3Cu(N0 3 ) 2 + 8NO3 4H2O 

Copper Nitric Copper Nitrogen Water 

Acid Nitrate Monoxide 

2. Neutralization of an acid by a base, 
the latter being an oxid, hydroxid, am- 
monia, or similar substance. Thus lead 
chlorid, sodium acetat, and ammonium ni- 
trat are produced by the reactions : 

PbO + 2HC1 = PbCl2 + H2O 
Lead Oxid Hydrochloric Lead Water 
Acid Chlorid 

NaOH + CH3COOH = H2O + CH3 COONa 
Sodium Acetic Acid Water Sodium 
Hydroxid Acetat 

NH3 + HNO3 = NH4NO3 
Ammonia Nitric Acid Ammonium Nitrat 

3. By the double exchange between two 
salts or an acid and salt, as in the prep- 
aration of Barium sulphat and Sodium 
hydrogen sulphat by the reactions : 

Ba CI2 + Na 2 S0 4 = BaSO s + 2NaCl 
Barium Sodium Barium Sodium 
Chlorid Sulphat Sulphat Chlorid 
NaCl + H2SO4 = NaHS0 4 + HC1 
Sodium Sulfuric Sodium Hydrogen Hydrochloric 
Chlorid Acid Sulphat Acid 

Other reactions forming salts are : — 

Na20 + H2SO4 = Na2S0 4 + H2O 
Sodium Oxid Suit uric Sodium Sulphat Water 
Acid 

Zn + H2S0 4 = ZnS04 + H2 
Zinc Sulfuric Acid Zinc Sulphat Hydrogen 
CaC0 3 + 2HC1 = CaClz + CO2 + H2O 
Cplcium Hydrochloric Calcium Carbon Water 
Carbonat Acid Chlorid Dioxid 

When a salt is formed from an acid and 
(Continued on page 78) 



tors and these require the following con- 
ditions of torque and speed: (a) Constant 
torque at variable speed; (b) variable 
torque at constant speed, and (c) variable' 
torque at variable speed. 

Q. 3. What is the object of the commu- 
tating field produced by the interpoles of 
a motor? 

A. 3. Its object is to assist commutation, 
that is to help reverse the current in each 
coil while short-circuited by the brush, and 
thus reduce sparking. 

WIRING QUERIES. 

(766.) W. Holsen, Buffalo, N.Y., de- 
sires to know : 

Q. 1. What are the disadvantages of 
open wiring? 

A. 1. The wiring is not sufficiently pro- 
tected from moisture . and the effects of 
fire which will destroy the insulation of 
the wires; it is also liable to mechanical 
injury. 

Q. 2. How far apart should the wires 
be placed if open wiring is used? 

A. 2. When installed in dry places and 
for pressures below 300 volts, the insulators 
should separate the wires 2J/2 inches from 
each other and ^2 inch from the surface 
over which they pass. For voltages from 
300 to 500 volts the wires should be sep- 
arated four inches from each other and 
one inch from the surface along which 
they pass. When wiring in damp places 
or over metal ceilings the wires should be 
at least one inch from the surface. 

Q. 3. How should wires be protected 
when run vertically on walls? 

A. 3. They should be boxed in or run in 
a pipe. The .covering should extend six 
feet above the floor. 



QUESTION BOX. 

(Continued from page 50) 
motor for a given service. There are three 
general classes of work performed by mo- 



RADIO-TELEPHONY. 

(767.) Marion L. Brown, Oroille, in- 
quires : 

Q. 1. Please advise me as to whether the 
hook-up which I send you will work on 110 
volts, alternating current, using an ordi- 
nary telephone transmitter. If this hook- 
up will not work, please send me a simple 
hook-up that will work on 110 volts A.C., 
using telephone transmitter and one that is 
inexpensive to make. 

A. 1. The diagram of connections which 
you submit will not work satisfactorily and 
wish to inform you that in order to make 
a radiophone operate on A.C. that you con- 
nect the transmitter in series with the pri- 
mary of the oscillation transformer. An 
ordinary microphone as employed in tele- 
phone practise will handle not more than 
one-half ampere, so that it will be neces- 
sary for you to confine your power below 
J/2 KW. If more power is to be controlled, 
then several microphone transmitters will 
be required in parallel and their mouth- 
pieces brought to a single mouthpiece. 

WAVE LENGTH PROBLEM. 

(768.) Wm. H. Mansfield, Jr., Putnam, 
Conn., desires : 

Q. 1. What is the wave length of an 
aerial 144 feet long, 50 feet high and a 
70 foot lead-in? It is a three-wire aerial. 

A. 1. The wave length of your aerial is 
320 meters. 

Q. 2. What is the wave length of an 
aerial 6 wires 30 feet high and 35 feet 
long? 

A. 2. The wave length of this antenna 
is 110 meters. 

Q. 3. What is the smallest sized spark 
coil an Oscillation Transformer can be 
used on efficiently? 

A. 3. This will depend upon the antenna 
system and the wave length which you 
desire to tune. It may be said in general 
that two turns will be the least number 
that the coil will require. The primary 
winding has less turns than those of the 
secondary. 

(Continued on page 54) 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



53 



TRAUtMAKlC 




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Patented May 2nd, 1916 

A first class Wireless Detector is half the battle in the wireless 
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Crystal Detector? 

Why Is Our Detector Near Perfection? 

Being a user of an Audion Bulb and having firmly, after due test and consideration of "mineral 
detectors," discarded them as unstable and unreliable and very inconvenient, being hard to keep 
in adjustment, I was very skeptical as to Lenzite, but glad to make the test and more than pleased 
that I did so. 

I found that the reception of signals with Lenzite as a detector quite beyond any hopes that 
I may have had. 

Inasmuch as the mineral in question (Lenzite) seems to be "sensitive" nearly all over its sur- 
face on all sides, which is a very great advantage as it makes it almost as easy 
to keep in adjustment as an audion, and brings in the signals, when proper 
attunement is accomplished, in a very loud and positive manner, and I must 
add I was greatly surprised as it, without any question, has given me far 
greater results than any other sort of mineral detector I have tried, and I have 
tried to get all that I have been able to hear of. 

Its clear, loud, readable demonstrations should make it very desirable to 
operators whether or not they use audions, which consume power which Lenzite 
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(6 IH U.S. License.) 



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54 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



THE STORY OF FLASHLIGHT 
MAKING. 

All of us have undoubtedly found the 
electric flashlight extremely useful at some 
time or other, but very few people are 
privileged to know just how the flashlight 
is made. One of the leading manufactur- 
ers of these useful devices recently con- 




1 



CtfNfll* 




Interesting Exhibit Which Tells the Story 
light Making Grafically. Every Important 
Manufacture Is Clearly Shown. 

structed a display board containing the es- 
sential parts constituting a complete flash- 
light, the appearance of which may be 
judged from the accompanying illustration. 
It was used by the bureau of visual instruc- 
tion of the University of California as a 
traveling industrial exhibit. The upper two 
rows represent the various stages of man- 
ufacture thru which a coat pocket style 
flashlight passes. The lower three rows 
show the progressive steps in the making 
of a tubular flashlight. A similar visual 
exhibit prepared by the same concern 
showed in a striking and educational man- 
ner, the various stages of flashlight battery 
make-up ; from the zinc plate to the as- 
sembled battery, consisting of two or more 
cells nestling comfortably in its paper car- 
ton. 



The Detroit Edison Company 'has made 
a number of tests with different methods 
of electrically heating cars stored in un- 
heated garages. Various means of heating 
insulated and uninsulated garages have 
been tried and experiments made with 
nearly all of the heaters sold for heating 
the engine itself. The results of these tests 
are now being worked up, and they will 
probably be presented in a paper at one 
of the conventions during the summer. 



control the machine automatically in case 
the pilot is unable to get positive control 
of the machine. 

The only real solution so far to this prob- 
lem involves the use of the gyroscope and 
the work done bv Mr. Elmer Sperry in this 
line gives much light to the solution. Fig. 
5 illustrates the Sperry automatic pilot 
which relieves the pilot of the 
labor and drudgery in operating 
the controls of his machine. In 
the military aeroplane it renders 
it possible for the pilot to ful- 
fill the duties of both pilot and 
observer. When dropping bombs 
it enables the pilot to bring the 
aeroplane laterally over the tar- 
get, makes a reference plane of 
the aeroplane, which greatly in- 
creases the accuracy of bomb 
dropping, and creates a steady 
platform from which to fire and 
drop bombs. 

The equipment consists prin- 
cipally of three units — the gener- 
ator, servo motor and gyro unit 
■ — which may be likened respec- 
tively to the heart, muscles and 
brain of the human pilot. 

The gyro unit which is placed 
in a metal case and shown in 
the background utilizes the gyro- 
scopic effect of the four rotating 
gyros which it contains, in main- 
taining a horizontal reference 
plane. Any departure of the 
aeroplane for its set relation to 
this gyroscopic reference plane 
causes an electrical contact to be 
made which completes a circuit 
to one of the magnetic clutches 
in the servo motor. The case is 
equipt with a glass window to 
enable the operator to note the 
joperation of the four gyros. The power 
generated in the servo motor air turbine 
is now transmitted thru the engaged clutch 
to one of the drums over which the control 
wire passes. 

The generator which is seen in the fore- 
ground of the photograph supplies alter- 
nating current for driving the gyros and 
direct current for the servo motor clutches. 
It consists of a double armature, one wind- 
ing of which is tilized for the generation 
of the alternating current and the other 
for direct current. It is driven by means 
of an aluminum propeller driven by the air 
current. The four leads are run from the 
rear to the generator. 

By means of a special set of clutches on 
the gyro unit, the operator can set the 
aeroplane to any position relative to the 
horizontal which he may desire, by simply 
pressing a button located conveniently on 
the manual control and moving his con- 
trols as tho no automatic nilot were in- 
stalled on the machine. When the aero- 
plane reaches the desired altitude, the but- 
ton is released and control is again given 
over to the automatic pilot, which will hold 
the machine in that altitude until altered 
by the operator. 

Complete and unhampered control may 
be instantly resumed at any time by press- 
ing on the push button on the controls. 



of Flash- 
Stage of 



ELECTRIFYING THE AEROPLANE. 

(Continued from page 7) 
ward the exact amount which is likewise 
shown in degrees. The scale is coated with 
Radium paint so that it is visible at night 
by its own light. 

One of the greatest problems of aero- 
nautical engineering is that of making the 
aeroplane as safe as possible. Thousands 
and even hundreds of thousands of dollars 
have been spent in this direction and the 
nearest conclusion to this problem is the 
adoption of some automatic pilot, which will 



WAR CONFERENCE WITH TELE- 
GRAPH AND TELEPHONE 
OFFICIALS. 

Messrs. Theo. N. Vail, president of the 
American Telephone and Telegraph Com- 
pany; Newcomb Carlton, president of the 
Western Union Telegraph Company; 
Charles P. Bruch, vice-president of the 
Postal Telegraph-Cable Company; F. B. 
McKinnon, vice-president of the United 
States Independent Telephone Association, 
and N. C. Kingsbury, vice-president of the 
American Telephone and Telegraph Com- 



pany, were in conference with war depart- 
ment officials at Washington on March 19 
to perfect plans to insure the government 
rapid and efficient wire communication. 

QUESTION BOX. 

(Continued from page 52) 
WAVE MOTORS. 

(769.) G. H. G., Detroit, Mich., in- 
quires as to the efficiency and practicability 
of wave motors : 

A. 1. We do not know just now of any 
successful installation of such wave power 
plants as described in the February issue of 
this journal and while the initial cost of 
installing such a plant is not so prohibi- 
tive, there has always been more or less 
prejudice against them, owing to the fact 
that the power developed is so irregular. 

There have been a number of attempts 
made by inventors to overcome this dif- 
ficulty, but the fact of the matter remains 
that we have yet to see a practical instal- 
lation of a wave motor on any large scale. 
The proposition to our mind seems to 
possess many practical and economic fea- 
tures, and it seems very likely that in later 
years a future generation may see the ad- 
aptation of wave motors to a very large 
extent. 

You may obtain copies of the patents 
issued on this interesting subject by com- 
municating with the U. S. Patent Office, 
Washington, D.C., and with these before 
you, you will be in a better position to see 
just what has been done and what has 
been proposed in solving this problem. 

CONDENSER IN AERIAL CIRCUIT. 

(770.) Anthony S. Detrees, Hartford, 
Mich., asks : 

Q. 1. Can a series condenser be used 
successfully in connection with a trans- 
mitter, to reduce the natural wave length 
of an aerial from 325 to 160 meters? 

A. 1. Yes. 

Q. 2. Would such an arrangement re- 
sult in low efficiency in transmitting? 

A. 2. The addition of a condenser in 
series with the antenna circuit increases 
considerably the amount of losses and at 
the same time increases the decrement due 
to an increase in antenna resistance by the 
series condenser. 

12 VOLT LIGHTING PLANT. 

(771.) U. J. Grant, Apple Creek, Ohio, 
writes : 



Wiring Diagram for 32 Volt Lighting Plant. 



Amp. 



Volts 




Fie/dcoih 

w Arm I 
U-W-J7 i 

0/4/r.Cir/nst 



COll 




6ra/ndedon ul 
90s engine frame 



To second 
bat. if used 



0771 



Lamps 

Sm'tcbes 

L °/?fi<tJ rubb. cor 
wire on up to so -40 
ft. circuits Forlongei 
circuits use iorger 
iv ires. 

© 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



55 



Q. 1. I would like to have a wiring dia- 
gram for a 32 volt isolated lighting plant 
with the following apparatus: Y\ K.W. 
generator, 32 volt 60 ampere-hour storage 
battery, switchboard with voltmeter, zero- 
center ammeter showing charge and dis- 
charge, circuit-breaker, regulating rheo- 
stat for generator and proper fuses and 
switches. 

A. 1. The accompanying wiring dia- 
gram gives the connections of a complete 
32 volt lighting plant. 

Q. 2. What is the wave length of my 
inverted "L" type aerial, composed of one 
wire 400 feet long, 70 feet high at one end 
and 40 feet at the other, with 30 feet lead- 
in and 20 feet ground (No. 4 copper 
wire) ? 

A. 2. The wave length of your antenna 
is 617 meters. 



Ohio, 



DYNAMO QUERIES. 

(772.) George Ledly, Cleveland, 
desires to know : 

Q. 1. Can a 12 volt, 9 ampere dynamo, 
such as the "Electro" Hercules charge suc- 
cessfully two 6 volt, 100 ampere-hour stor- 
age batteries in series? 

A. 1. Yes. They should be connected 
in parallel, however. 

Q. 2. Can a 25 volt, 4 ampere dvnamo 
be run in series with four 6 volt 100 am- 
pere storage batteries to produce 50 volts? 

A. 2. Yes, providing that the batteries 
are fully charged. It would be advisable 
to employ an underload circuit breaker in 
the storage battery side so that they will 
be disconnected when they are in a dis- 
charged condition, thus preventing the 
charging of the battery by the dynamo in 
an opposite direction, in this way prevent- 
ing the plates from being ruined. 



The Trade-Mark of 

Efficiency 

in wireless transformers is the word "Thordar- 
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be a mighty good reason why so many expert 
operators are satisfied only with a 

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THE ELECTRICAL EXPERIMENTER 



May, 1917 



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Established 1914 Erie, Penna. 



Generators! Alternators! 

We have a complete line of sturdy, efficient gen- 
erators and alternators from 100 to 1000 watts. 
We furnish complete parts for these finished ready 
to assemble with instructions to wind. Trans- 
formers made to order. Send for catalogue. 

ALL AT FACTORY PRICES 
Bergmann Motor Works, 442-446 Niagara St., Buffalo, N.Y. 



INDIRECT LIGHTING. 

(773.) J. Andrews, San Francisco, Cal., 
inquires : 

Q. 1. What is meant by indirect lighting 
and what are its characteristics? 

A. 1. Indirect lighting as the name sig- 
nifies is illumination in which the light 
comes to the working plane indirectly. The 
light of the lamp is directed at the ceiling 
by suitable reflector appliances, and from 
there is diffusely reflected into the room, 
making the ceiling a secondary light source. 

The enlarged low brilliancy source of 
light, the ceiling, produces a highly uni- 
form and diffuse illumination, free from 
glare. Shadows are softened and merge 
very gradually into the brighter areas. 
There is practically no glare or reflection 
from glossy surfaces. Recent tests ap- 
parently confirm the general belief that 
indirect lighting requires minimum inten- 
sity of illumination for comfortable vision 
and causes very low fatigue of the eye 
as a result of several hours' work. 

Q. 2. What are the chief considerations 
in planning an adequate lighting installa- 
tion ? 

A. 2. Planning a lighting installation is 
a complex problem, requiring due consid- 
eration of a number of factors. The in- 
tensity of illumination must be ample for 
clear comfortable vision; the distribution 
must be nearly uniform over the working 
plane. The color of the light must be 
suitable for the class of service, and the 
taste of the individual and the diffusion 
must be satisfactory for the class of serv- 
ice. The sources of light must be placed 
well above the range of vision' and the in- 
trinsic brilliancy reduced by the use of dif- 
fusing" glassware or indirect reflector equip- 
ment; shadows on the working plane must 
be softened and toned down so as not to 
be too abrupt and for drafting rooms, 
operating rooms, etc., practically elimina- 
ted; objects capable of high specular re- 
flection (glossy objects) should be re- 
moved from the range of vision. 



POWER HOUSE PROPOSITION. 

(774.) Paul Wheadon, New Brunswick, 
Ga., wants : 

Q. 1. What types of power houses are 
used by large factories as we desire to 
equip our plant with an electric equipment? 

A. 1. There are several types in com- 
mon use. Some factories use 125 volts 
direct current. However, 220 volts direct 
current is popular araon? steel mills. The 
larger ones sometimes use 500 volts. Al- 
ternating current is largely used, induc- 
tion motors being employed to drive ma- 
chines or line shafting. Cranes are most- 
ly operated by direct current, altho alter- 
nating current may be used for this pur- 
pose. 

Q. 2. What arrangement of excitation 
is customary? 

A. 2. Direct current generators are us- 
ually self-excited. Alternators usually re- 
quire separate excitation which is had 
from a relatively small direct current gen- 
erator. It is preferable that the exciters 
should have a separate prime mover if 
space economy is possible, tho many ex- 
citers are driven by the same engine that 
drives the main generator. 

Q. 3. What considerations determine the 
voltage of a transmission line? 

A. 3. The voltage of a transmission line 
is found by a careful study of the ad- 
vantages of very high voltages in permit- 
ting the transmission of a large amount 
of power on a small conductor; the ad- 
vantages of lower voltages because of 
the greater ease of insulating, the dis- 
tance to be covered and the nature of 
the country thru which the line is to be 
run. Due consideration is also given to 
the first cost of power. If it is obtained 



from water power or from very cheap 
coal, it may be best to design for rela- 
tively high line losses. If coal is trans- 
ported a long distance, it is therefore ex- 
pensive, and the line must be designed for 
low losses. Each case requires special 
study by experts. 

INDOOR AERIAL. 

(775.) Mr. Shane, Grand Rapids, Mich., 
says : 

Q. 1. Kindly let me know what an in- 
door aerial is made up of and the dis- 
tance one can hear with the same. 

A. 1. An indoor aerial is nothing more 
than an ordinary antenna which is erected 
indoors. The distance which one can re- 
ceive with such an antenna depends en- 
tirely upon the sensitivity of the instru- 
ments used with this type of aerial. 

Q. 2. Kindly let me know where I can 
get full set of rules in reference to size 
and power receiving and sending set the 
Government will allow one to have and 
what is necessary to pass examination to 
allow a large set to be erected? 

A. 2. We advise you to communicate 
with the Radio Inspector of your district 
who will give you all the information you 
desire. 

Q. 3. Kindly let me know if it is al- 
ways necessary to have a wire run all 
the way down to the earth to make a 
ground and if one is in a hotel on the 
ninth floor or higher up, how he can make 
a ground without having to let a wire 
down to the street at the same time want- 
ing it to be safe from all danger to prop- 
erty or in case of lightning and if the 
apparatus will be just as efficient in re- 
ceiving. 

A. 3. It is not necessary to run a wire 
down to the ground if a water or gas or 
even a radiator pipe is located near the 
station. However, in erecting a lightning 
ground it is necessary for you to wire 
from the lightning switch to the outside 
ground, which must connect from the 
ninth floor as in your case. The sensi- 
tiveness of the receiving outfit will not 
be lowered by this ground. 



RECEIVING RADIUS. 

(776.) Harry Cate, Chattanooga, Tenn., 
inquires : 

Q. 1. Can a loose-coupler, a tuning-coil 
and a loading-coil all be used together 
successfully? 

A. 1. Yes; providing they are properly 
connected. 

Q. 2. What would be the range of the 
following set with an aerial 45 feet long 
and 40 feet high if question (1) is cor- 
rect; a small tuning coil (E., I. Co.'s 
"Electro" tuning coil), a small loose coup- 
ler (E. I. Co.'s "Electro" loose coupler) ; 
loading coil with wave-length 5,000 meters, 
galena detector, 2 fixt condensers and 
3,000 ohm head set. 

A. 2. The approximate receiving range 
of your apparatus is 1,500 miles. 



SERIES CONDENSER. 

(777.) John Huether, Sharon, Pa., in- 
quires : 

Q. 1. Is it necessary to use a series con- 
denser with a transmitting set on an 
aerial 75 ft. long and 55 ft. high? 

A. 1. A series condenser in the trans- 
mitting circuit is not necessary if the set 
is tuned to its natural period of 200 meters 
as permitted by the Government. With 
the aerial you possess it will not require 
a condenser in series. 

Q. 2. Are you allowed to have an input 
of over 9.1 amperes on a 1 K. W. trans- 
former to comply with Radio Regulations, 
or can you have whatever input the trans- 
former will draw? (Operated from 110 
volts A. C.) 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



57 



A. 2. 9.1 amperes of current at 110 volts 
A.C. is just permissible. However, we 
would advise that the transformer should 
be operated on 9 amperes so as to be on 
the safe side. 



HYDROGEN GENERATION. 

(778.) W. H. Allum, Quebec, Canada, 
asks ? 

Q. 1. Would it be practical to make a 
small apparatus to generate hydrogen gas 
by the decomposition of water by direct 
current if so, kindly send me a rough 
sketch of apparatus mentioned. 

A. 1. The most practical and inexpen- 
sive method of generating hydrogen gas 
is by the decomposition of water by a di- 
rect current. In this work, it is essential 
not to employ too great a voltage, but a 
large current. There has been a large 
number of different types of hydrogen 
generators developed but the one de- 
scribed on page 547 in February, 1916, 
issue of this journal will be found most 
suitable for the making of a small ma- 
chine. Not only will you be able to obtain 
hydrogen gas but at the same time and 
with the same current and water you will 
obtain oxygen gas. 

Q. 2. Would hydrogen gas generated in 
this manner burn by itself, the flame to 
be used for the purpose of lead burning 
in connection with the repair of storage 
batteries and lead containers for the same? 
I have access to 125 volt D.C. up to 60 
amperes. 

A. 2. The hydrogen gas generated by 
this electrical method will be required to 
be combined with oxygen making the so- 
called oxy-hydrogen blow pipe. This 
oxygen will be obtained from the same 
generator. The gas produced will be re- 
quired to be collected in some reservoir 
chamber equipt with proper safety valve?. 

Q. 3. Has this gas any injurious effect 
on metals ; if so what metals are suitable 
for the construction of such apparatus. 

A. 3. Hydrogen gas has no injurious 
effects upon metals, but when combined 
with oxygen and ignited they will be 
molten as it produces terrific heat, the 
value of which is next to that of the elec- 
tric arc. 

TRANSMITTING SET. 

(779.) F. Gibbons, Toronto, Ont., asks: 



luenched gap 



— / 1 

Key Kick back 
preventer 



Hotwice J 
Ammefer 



Correct Hook-Up for Quenched Spark Radio 
Transmitting System. 



Q. 1. What instruments are required to 
make a transmitting set efficient? How 
do you connect them? 

A. 1. The following instruments will 
be required and operated on 110 volts 
alternating current: l /, K.W. 10,000 volt 
transformer, kick-back preventer shunted 
across the primary of the transformer, 
heavy key, high tension condenser hav- 
ing a capacity of .015 microfarad, 5 sec- 
tion quenched spark gap, oscillation trans- 
former and hot wire ammeter used for 
indicating the amount of radiation in the 
antenna system. The connections of the 
instruments are given here. With the 
above mentioned instruments and an aerial 
composed of 6 wires 50 feet long and 60 
feet high, you should have no trouble in 
covering a distance of 80 to 100 miles. 




50^ Week 



YES, for this insignificant sura you can get the great 1916 edition of the Cyclopedia 
of Applied Electricity. See it before you decide to buy. No matter what you 
want to know_ about electricity — here it is at your fingers' tips. The great author- 
ities have written it in plain English — so that you can grasp it instantly. These books 
mean more money for you — promotion — the position you have been dreaming about, 
and all you need to do to get the entire seven volumes is to send us your name and 
address. Use them seven days at our expense before you decide if you want to buy. 

All About Electricity! 

The 1916 edition of Cyclopedia of Applied Electricity contains 3,200 pages, 7x10 
in.; 3,000 illustrations, full-page plates, diagrams, etc. ; hundreds of valuable tables and 
formulas; carefully cross-indexed for quick, easy reference. Printed on special quality 
paper and bound in half red morocco, gold stamped. Seven volumes. The standard 
of America — the information that is vital to you and to every man who is interested 
in electricity. And it is yours — on a startling offer. 



Shipped FREE! 



Don't send us 
a penny. We 
will send the 

entire seven volumes prepaid right to your home, so that you 
can see and examine them for yourself. Keep them seven 
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If you think you can, send them back. If you keep them, 
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sole judge — you do not risk a penny. This offer is open to 
everyone in the U. S. and Canada. 

Consulting Service FREE ! 



Read These Subjects 

Elements of Electricity — 
Electrical Measurements 
— Underwriters' Require- 
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and Motors — Dynamo- 
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Lighting Machinery — 
Power Transmission — 
Electric Railways— Power 
Stations — Switchboards 
and Switching — Storage 
Batteries — Applied Elec- 
tro-chemistry— Electric 
Elevators— Electric Weld- 
ing and Heating — Wire 
and Wireless Telegraphy. 



Send the Coupon / w 



A year's Consulting Membership (regular price $12.00) will f . . _ . . 
be given free if you send your order at once. [The advice of / American Technical Society 
an entire corps of electrical experts is yours — to help you » I?? 4- E 7i4S , Chica(t(l1 ' U -S.A. 
in your progress-for a whole year FREE! , of gXiSStSSt^SSS 

♦ days' free examination. If I 
keep the books will send $2.00 
within seven days and $2.00 a 
month until $19.80 has been paid, 
when books and Consulting Member- 

See these books for yourself before you decide to buy. / n s h t j? y ^ a b n e d bo^Tullectl!! 

Remember — don t send us a penny. Just fill out * your order, 
the coupon and mail it. We'll send you the entire t * 
seven volumes prepaid. Use them seven days — # 

then if you want to buy pay the special reduced price at Name 

the rate of $2.00 a month. Send the coupon now. Your f 
ambition says — act — see for yourself. t 

AMERICAN TECHNICAL SOCIETY 

Dept. E. 7445 CHICAGO, U.S.A. 



Address 

As I have had 1 



> previous dealings with you. I refer you to 



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5 8 



THE ELECTRICAL EXPERIMENTER 



May, 1917 




NATIONAL 
CALLING 
SYSTEM 



Finds Executives 
Instantly! 

On the Dock On Shipboard 

ON long, dimly lighted docks, piled 
high with merchandise, it is not 
easy to get into immediate com- 
munication with Superintendents or 
Foremen. On shipboard, too, Officers on 
tours of inspection or off duty may be 
wanted urgently — and no one knows 
where they are. 

But the National Calling System will 
find such men at once. To illustrate: 
The telephone operator, having been in- 
structed to find Mr. Smith, sets the 
small levers on the calling instrument 
for his code number and then gives the 
operating key a quick turn. Instantly, 
this code number is sounded simultane- 
ously all over the dock or vessel, as the 
case may be, on electric chimes, horns, 
buzzers, or whatever signaling devices 
are in use. 

Mr. Smith cannot get out of hearing of 
one of these signals, no matter where he 
goes. He gets his call instantly and 
immediately answers from the nearest 
telephone or reports in person. 
No Executive or Officer on ship or dock 
can afford to be out of reach. The 
National Calling System enables him to 
go where he will because he can be found 
instantly, at any time. 

Send for Complete Information 
and Descriptive Booklet No. 34. 

NATIONAL SCALE COMPANY 

(ELECTRICAL DIVISION) 
5 RAPIDS STREET, CHICOPEE FALLS, MASS, 

Also Manufacturers of [National Counting Machines 
and National-Chapman Elevating Trucks 




RADIO WIRING DIAGRAM. 

(780.) Experimenter Reader, Pleasant 
Plains, 111., desires : 

Q. 1. Please give me a diagram of the 
following instruments for both damped 
and undamped wave reception : Loose 
coupler, loading coil, Audiotron bulb, ga- 
lena detector, buzzer and push button, two 
variable condensers, 'phones and a large 
loose coupler for undamped waves. 
Please give necessary switches for chang- 
ing from damped to undamped for either 
detector, and for using the variables on 
either the damped or undamped set. Also 
the necessary loading inductances in the 
undamped circuit if there has to be any. 

A. 1. We give herewith a complete 
wiring diagram of a damped and un- 
damped receiver, showing the necessary 
switches. 

Q. 2. Could this set receive music on 
the undamped wave? If not, please tell 
me how? 

A. 2. Yes, providing the Audiotron tube 
is set oscillating. 

Q. 3. The probabilities of Congress put- 
ting a stop to, or shutting down the Ama- 
teur stations of the United States? 

A. 3. The 1912 radio law provides that 
the President has authority to close all 
radio stations in case of war. 




si <? 



DPDT sry 

Audiotron 



r,.— Buzzer 




Hook-up for Audion and Crystal Detectors 
to Be Used in Receiving Damped and Un- 
damped Radio Signals. 



AUTOMOBILE SPARK COIL. 

(781.) Leo Peterson, Thorsby, Ala., 
wants : 

Q. 1. Would an automobile coil with 
three binding posts giving a spark inch 
long work all right for wireless? 

A. 1. It will work satisfactorily for 
transmitting a short distance. 

AEROPLANE RADIO GROUND. 

(782.) George Sloan, St. Louis, Mo., 
writes : 

Q. 1. I would like to know the address 
of Dr. Nikola Tesla. 

A. 1. The address of Dr. Nikola Tesla 
is 8 West 40th St., New York. 

Q. 2. How do aeroplanes get a ground 
for their wires. 

A. 2. By suspending a wire from the 
aeroplane which trails behind the machine. 

RADIO ARC TRANSMITTER. 

(783.) Mr. , Pittsburgh, Pa., asks 

several questions regarding an article on 
an Arc Type Radio Transmitter by Mr. 
Gordon C. Farmer, which appeared in the 
February issue : 

A. 1. It is possible to obtain a fairly 
high note with such an arc transmitter, 
especially if the arc is shunted with a suit- 
able tone circuit after the method of Von 
Lepel. You might use a 43 plate Murdock 
variable condenser or the equivalent, pro- 
viding the plates are immersed in oil. 
The size of the plates in the arc would 
remain the same for mica instead of 
paper; paper has been found best for this 



HIGH FREQUENCY OUTFITS 




We specialize in all forms of high frequency appa- 
ratus, including apparatus for generation of Violet 
rays for medical treatment and sterilization of 
water. X-Rays. etc The outfit illustrated is 
only one of three sizes we build ranging in 
price as follows: $25.00; $35.00; $50.00. We also 
supply all forms of high frequency electrodes. 

ROSENTHAL LABORATORIES, Camden, N. J. 



SEAMLESS CARDBOARD TUBING 



♦ IN SIZES SUITABLE FOR ♦ 
^Tuning Coils, Loose Couplers, Tesla Coils, Etc. 
4PRICE LIST— Smooth Wound Wireless Tubes* 

♦ Outside Lgth. Price Par,\ GENERAL INFORMATION ♦ 

Post 




GENERAL INFORMATION 

These prices include PARCEL 
POST CHARGES: and are 
shipped at once on receipt of 
order and remittance. 
We CANNOT furnish these 
tubes in longer lengths than 
7H* unless ordered in quan- 
tities of 100 of a size. 

We CAN furnish SPIRAL 
WOUND TUBES in any 
length up to 45 inches at .02 per 
inch in the following Inside 
. diameters. 313-4-4). i -5-6. 
SPECIAL GRAY TUBES 
x6%" $lea. 18"x7^"x7Jf 



I8"x6M"x6^" $lea. 18"x7^"x7%" $1 ea. & 

| BEETLE & MACLEAN MFG. CO. f 

A 21 BROMFIELD ST. BOSTON, MASS. X 

^^^^^^^^^^^^^^^ 



F 



ORMICA 

An Insulating Material of Excep- 
tionally High Dielectric and Me- 
chanical Strength, Waterproof, 
Heat Resisting and Permanent. 



Supplied in Jet Black or Brown Sheets. 
Also Furnished in the form of Finished 
Panels accurately cut to specifications. 



THE FORMICA INSULATION CO. 



CINCINNATI, OHIO 



Electro-Set Arf»n6ton Tested 
WIRELESS MINERALS 




i your 

25 



When you place an Electro-set 
Arlington Tested Crystal in your 
detector you KNOW that it " 
is sensitive. Every crystal 
is carefully SELECTED «, « 
and TESTED before beine „ 
individually PACKED and tent8 
SEALED under our label. Electro- 
set N. A. A. minerals have proven 
their superior worth in actual 
service throughout the world. 
Sold by leading dealers or by mail 
direi-t. Silicon or Galena 25 cts each. 

THE ELECTRO-SET CO. 
Dept. E-12 Cleveland, Ohio 



STROMBERC . CARLSON <C0.25 
RADIO HEAD SET 



Stromberg - Carlson Telephone Mfg. 
Rochester, N. Y. 



Co. 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



59 



purpose after exhaustive experimentation. 
The paper is pierced with a pin-hole at 
the center when assembling the arc gap, 
and also it is extremely important as to 
just what kind of paper is employed — one 
of the best papers for the purpose hav- 
ing been found to be a certain kind of 
water line bond. The editor of this col- 
umn does not recollect just now as to 
who made this paper, but you can obtain 
the name of the concern supplying this 
particular writing paper by communicating 
with the Institute of Radio Engineers, New 
York City. 

An arc may be started with 500 volts 
using a small gap of 1/100 inch or so, 
especially where the circuit is made and 
broken by a quick break switch. The 
transformer described by Mr. Farmer 
would be rated at about one-half kilo- 
watt. 



FORMULA AND RECIPE BOOK. 

(784.) Tom Otis, Cedar Rapids, Iowa, 
writes for information on a book contain- 
ing formulas and recipes : 

A. 1. You will find books containing sev- 
eral hundred different formulas listed in 
our Book Catalog, which we shall be 
pleased to forward you on request. We 
shall also continue to publish a number of 
these formulas monthly in The Electri- 
cal Experimenter. 



ELECTRICITY AND LIFE. 

(Continued from page 24) 

like discharge three feet in diameter (Fig. 
1), and gives a heavy arc over two feet in 




How Small Size Tesla Coil for Medical Treat- 
ment Is Built; "b" Is the Primary, "a" the 
Secondary. 



length. (Fig. 2.) This shows remarkable 
efficiency when it is considered that the re- 
sonator is excited by a "Type E" trans- 
former drawing only 1 K.W. and a con- 




Unique Stationary Spark Gap Having 
Grooved Faces, as Devised by Dr. Strong. 

denser of but .01 m.f. capacity. A small 
rotary spark gap is used such as is sup- 
plied by the E. I. Co. This result is made 
possible by the use of the separate induc- 
tance in series with the resonator primary 
(exactly the same as that described in con- 
nection with the therapeutic apparatus) 
(d Fig. 8). The writer believes his re- 
sonator gives the most spectacular dis- 
charge ever obtained from 1 kilowatt of 
energy. 

Ordinary plate condensers are used, made 
from 8 x 10 inch negative glass, coated on 
both sides with tin-foil 6x8 inches (a Fig. 
7). Six pairs of plates assembled into a 



QST 



AMATEURS! 




Knob Only 



No. 20 No. 21 

Build your own receiving sets and save money. Handsome knobs 1 inch high and ] 1-4 inch and 2M 
inches in diameter. Brass Collar 5-16 inch high. Self cleaning switch lever 1-18 inch and 1-14 inch long. 
These switches will make any set look 100 per cent better. 

Club together and buy them in 100 lots at the following orices: 
No. 20 Switch complete - - per 100 $52.00 No. 15 Brass contacts 1-4 in. 

" 21 " - - " 36.00 x 1-4 tapped 6-32 - per 100 $1.75 

44 1 Knob only - - - - 44 30.00 44 1 4 Brass contacts 5-16 in. 

44 2 4 4 44 - - - - - 44 1 5.00 x 5-16 tapped 6-32 - 44 2.50 

ROTARY GAP DISCS 



5 3-4 inch 
diameter 

1-8 inch 
I thick 




Carrying 
capacity 
2 K. W. 



Made of highly polished Formica and turned absolutely true. Guaranteed not to warp or crack. "A" 
™c represents our famous chord note rotary. Type "A" disc furnished with either 8 or 12 points — type 
"B" disc in 6-8 or 12 points at no additional charge. Chuck drilled 1-4 inch shaft. 

Disc complete with chuck - - - - $3.50 Chuck only - -- -- -- -- - .60 

" less 44 _____ 3.00 Ex for spec, drilled chuck up to 3-8 in. .30 

KLITZEN WIRELESS APPARATUS COMPANY, 1133 Herrick Ave., Racine, Wis. 



'NEW 



'NEW 



TWO COIL 
Amplifying Transformer 

Especially adapted and recommended for use with all tubular 
vacuum detectors. 
Result of six months work and great expense. 

10 TO 25 TIMES AMPLIFICATION 
Introductory Offer $9.90 

Delivery free anywhere in U. S. if cash accompanies order. 

ONE STEP AMPLIFIER PANEL 

Made of hard rubber with two 30 cell batteries without tubes. 
Price $30.00 Ready For Delivery 

Our new composition rheostat absolutely essential for efficient 
filament control for all vacuum detectors. Write for description. 

Satisfaction Guaranteed 
AUDIO TR0N SALES CO., 315 Lick Bldg., San Francisco, Cal. 



This Efficient Tuner Only $8.00 

"Your Tuners are very selective and efficient and highly praised by 
the members of the Auburn Y.M.C.A. Radio Club.— Robert Eccles, 
Secretary and Treasurer." 

Big Undamped Tuner, 20 taps on primary, 14 on secondary and brings 
in German stations fine, only SI. 5. 00. 

15,000 Meter Loading Inductance in quartered oak case with 9 taps, 
only $8.00. Send 2-cent stamp for bulletins. 

COLBY'S TELEGRAPH SCHOOL Auburn, N. Y. 




You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



6o 



THE ELECTRICAL EXPERIMENTER 



if u a dd u y namo 

tl WAT Eg m ri t 

nan AV1 u 1 

For Bo.ys $ 

For producing current for in- 
ductance coils, re-charging 
storage batteries, elec- 
troplating and hun- 
dreds of other uses. 
Well constructed 
throughout, exception- 
ally smooth running 
and highly efficient. A 
good, strong, durable 
dynamo. 

AT ALL LIVE DEALERS 

Insist on your dealer showing you the KNAPPline— 
KNAPP goods are best. If your dealer cannot supply 
you. order direct. Send for FREE illustrated cata- 
logue showing a complete line of Electrical Motors 
and Novelties ranging in price from 10c up. 

KNAPP ELECTRIC & NOVELTY CO. 

523 West 51st Street, N. Y. City 




ENCLOSED 
ROTARY GAP 

This gap has been designed 
to sell at a low price and to 
meet the demands of ama- 
teurs for a good, enclosed 
and silent gap. Finished in 
dull black.it will add tothe 
appearance of your set. 
It is made in one styleonly, 
for all powers up to I-KW, 
and can be mounted in al- 
most any position. 
The gap is enclosed in a 
circular iron housing 8 inches 
in diameter and 2}^ inches 
thick, with removable cover 
(for inspection). The adjust- 
ment can be as close as desired 
between sparking points. 
Rotating disc is of brass with 12 projecting 
round brass arms (total diameter 6 inches), 
mounted on shaft running in bronze bearing 
and is belt driven by small motor giving a 
variety of tones depending upon the speed. 

When in operation this gap is very quiet 
Price complete, without motor, $8.50 
J. Herbert Ferris, 211 Catalpa Drive, Royal Oak, Mich. 




ONE-INCH 



JUMP SPARK 
COILS for 
WIRE- 
LESS 

$3.25 

Guaranteed to jump as specified 
or money refunded. 

WISCONSIN IGNITION CO. 

609-513 Cedar Street, Milwaukee, Wisconsin 





Send two cent stamp 'or circulars 

CLIFF MFG. CO., Brookfield, Mass. 



unit and boiled in wax give a capacity of 
.01 m.f. For safety it is better to employ 
four of these sections connected in pairs 
of .02 m.f. each (b Fig. 7). To run this 
resonator at full power for long periods of 
time it would be safer to use a series 
multiple condenser consisting of three sec-. 




Connection Scheme for Tesla Coil "f — g," 
Shorting Switch "e." Tuning Inductance "d," 
Spark Gap "c," Condenser "b" and Step-up 
Exciting Transformer "a." 

tions of .03 m.f. each in series. Such a 
condenser would contain 108 — 8 x 10 inch 
plates, and would be expensive, bulky and 
very heavy. For this reason the writer has 
found it much more convenient to use a 
single 12 plat (.01 m.f.) condenser across 
the transformer secondary and to replace 
it when it punctures. The large resonator 
was operated for six months in lecture and 
experimental work before a condenser sec- 
tion broke down. 

The cone for the secondary of the large 
resonator is of hea paperboard and was 
built for the author by Bicknell and Fuller 
of Boston. Its dimensions (see Fig. 6) 
were suggested by Mr. Earle L. Ovington, 
the cone being similar in shape to those 
used by Mr. Ovington in the New York 
Electrical show several years ago. Any 
amateur can make a cone of this kind by 
superimposing strips of heavy paper, soaked 
in paste, over a wooden framework. The 
secondary winding consists of 400 turns of 
No. 27 D.C.C. copper magnet wire. Two 
parallel strands of wire are wound onto 
the cone, the adjacent turns in contact; 
after winding, one strand of wire is re- 
moved, leaving a space equal to the diam- 
eter of the wire between each of the 400 
turns. The cone and winding is then treated 
with several coats of "Armalac" (ordinary 
shellac will not answer). 

The primary consists of five turns of thin 
copper ribbon 1 inch wide, l /% inch paper- 
board strips being placed between the 
turns. The diameter of the coil is 24". 
When completed it is taped and rotated 
in a pan of melted wax until thoroly im- 
pregnated. The terminal shown in the pho- 
tographs is made from a large brass oil- 
can, the stem being removed and replaced 
by a 3" brass "bed-ball." The terminal is 
not attached to the cone but simply rests 
on its upper surface in contact with the end 
of the secondary wire. The primary and 
secondary are separately supported by 




Class plate s'-io' 
a I b 




Tinfoil 6''0' 



Condenser Details 
7 



Details for Building High Tension Glass 
Plate Condenser to Be Connected in Tesla 
Coil Circuit. 

quare wooden blocks ; the coupling is rather 
loose, the bottom of the resonator being at 
least two inches above the primary. The 
lower end of the secondary coil is attached 
to the inner primary terminal and grounded. 



May, 1917 

Oh, You Skinny! 

Why stay thin as a rail? You don't have to I 
And you don't have to go through life with a 
chest that the tailor gives you ; with arms of 
childish strength: with legs you can hardly 
stand on. And wnat about that stomach that 
flinches every time you try a square meal? 
Are you a pill-feeder? 

Do you expect Health and Strength in 
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and other exploited piffle ? 
You can't do it; it can't be done. 

The only way to be well is to build up your 
body — all of it— -through nature's methods — 
not by pampering the stomach. It is not FATE 
that is making you a failure; it's that poor, 
emaciated body of yours; your half -sickness 
sh- ws plain in your face and the world loves 

healthy people. So be HEALTHY STRONG- 

Th " 



Send4< 



that's living. Don't think too long; 
in stamps to cover mailing of my book; 



'Intelligence in Physical & Health Culture' 
written by the strongest physical culture 
INSTRUCTOR IN THE WORLD. 

LIONEL STRONGFORT 

Physical Culture Expert 
No. 95 Park Bldg., Newark. N. J. 



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DON'T BE THIN! 

Physical Perfection at- 
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PORCELAIN 

"THAT'S OUR BUSINESS" 

Standard and Special Shapes, Regardless 
of How Difficult 

We Illustrate one hard shape we make. 
A pair of rolls iy 2 " long and 1)4" in 
diameter with 8 holes on ends and middle. 
They must be perfectly straight and wo 
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We can make your difficult! designs also. 
Send ua blue print for quotations. 

Unioi Electrical Porcelain Works 

TRENTON, N. J. 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



61 



Perfect resonance is obtained by varying 
the number of turns in the inductance coil 
in series with the primary. (Fig. 8.) This 
tuning system enables us to perform many 
brilliant experiments otherwise impossible, 
such as illuminating wires stretched across 
a lecture hall, lighting an inverted um- 
brella, etc. Some new and very spectacular 
experiments with this large resonator will 
be described and illustrated in an article 
in next month's "Electrical Experi- 
menter," entitled "Methods of employing 
high-frequency currents in medical and lec- 
ture work." 

The author is greatly indebted to Mr. 
O. K. Luscolm, for advice and assistance 
which made possible the successful con- 
struction of the large resonator. 




b 



® F>9 8 Toqround 

Method of Connecting Transformer, H. T. 
Condenser, Rotary Spark Gap and Tuning 
Inductance "d" to Large Oudin Coil. 

At a recent lecture before the Belfast 
Association of Engineers Mr. A. W. 
Brown suggested the transmission of 
power generated from the tidal rise and 
fall of the water at Strangford Lough and 
Lough Neagh to Belfast. Thus, at Strang- 
ford Lough there are twenty square miles 
of water available, the spring tides have a 
rise of 14J/2 feet and the neap tides a rise 
of ll]/2_ feet, with a range of 7j/2 feet. 
About 20,000 horsepower could be devel- 
oped for a period of two and one-half 

THE WASHINGTON'S BIRTHDAY 
RELAY PRIZE WINNERS. 

{Continued from page 23) 
live in a state that has as much real earth 
in it as is blown into the air in some of 
our larger states during every wind storm ! 

These few think they are very impor- 
tant and if you don't do as they say, why 
the Government will close you up. They 
say "The Danger Signal is up." Did you 
ever hear of a good, red-blooded Ameri- 
can Kid who could be bluffed? No! It 
is not in your make-up. The Government 
is only too anxious for you to perfect 
yourself in the art, and help it out by 
joining the "Radio Reserves." 

PRIZES. 

This is a stunner for one who would 
like to give everybody that helped a prize, 
but it can't be done, so I am going to ask 
the boys who acted as sending stations to 
consider that they are one of the family 
and help me by agreeing that the prizes 
should go to the boys who made the best 
records in receiving and delivery. The 
rest of the amateurs will be rewarded by 
having their names printed in this maga- 
zine, so that when you grow older and 
have a little one on each knee in front 
of the old log fire, some cold night, you 
may read to them about Daddy and what 
he did when he was a mere boy. 

Before you all get busy reading about 
the prize winners, I want to call your at- 
tention to several hard workers who 
turned in the most complete reports, or 
"logs," of the relay, that the writer has 
ever had the privilege of reading. 

Hoyt, of Hayward, California, 6 SI, 
who is also a prize winner, turned in the 
most complete report ever seen. 

Stewart of St. Davids, Pennsylvania, 3 
ZS, whom you all know as one of the hard 
hours, the power available varying from 
maximum to minimum eve ry s ix ho urs. 



workers of the Radio Association of Penn- 
sylvania, turned in a truly wonderful re- 
port, but he stayed up till nearly 6 a.m. 
the next morning, boys, and from the 
looks of his "log," he went to sleep with 
the pen in his hand. It really only took 



me about two hours to digest this report. 

Emerson of Dallas, Texas, 5 DU, as 
ex-man-o-warsman, turned in a regular 
Navy Report, brim full of interest and 
curt reports. He, too, along about the 
dog watch, evidently slept on duty. Bet 



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Chemicals and Apparatus for the Experimenter 

We have just completed a price list of chemicals and 
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for a copy of this list. 1 1 will be valuable to you. 

THE PORTER CHEMICAL COMPANY 

Department B. Hagerstown, Md. 





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Magnetism — Induction — Experiments — Dynamoa ■ — 
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02 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



he is glad he wasn't aboard the good ship 
"Hardship," as they shoot men in war- 
time for sleeping on duty. He was right 
on deck tho, all the time, and the writer 
could clearly read his calls to 9 ZF and 
answers to the boys east. 

The boys of the San Francisco Radio 
Club also made splendid reports, as did 
also our College Professors, who are al- 
ways with us. 

A perfectly legal report was also re- 
ceived from a staid old lawyer in Jack- 
sonville, Fla., who prefaced his letter with 
the remark that he was not trying for a 
prize, but being a "Radio-Bug," he just 
could not keep still. 

A well known D. D. S. in Elmira, also 
sent in a very complete report and called 
it a great night's work. 

I just compared two interesting letters 
from one amateur. 

iqi6. He was diligently stabbing a piece 
of galena and complaining about his vi- 
brator sticking 011 his one inch coil. Said 
he did not get M.S.G. but thought he would 
report anyway. 

1917. He sent me a list of stations he 



hears, as long as your arm, and he is now 
sporting a one K.W. and working as a star 
relay station, 1,000 miles being as nothing 
to him. I heard him from my station — 
clear, quick sending; prompt business- 
like signatures, and abbreviations that 
went clear over my head. "The world 
do move!" 

PRIZE WINNERS. 
Mr. E. B. Duvall and Mr. A. P. Smith 
are awarded the prize of the Electro Im- 
porting Company — their ''Nauen POZ" Ra- 
dio Receiving Set! These young men 
operate jointly the Radio Station, 3 AK, 
in Baltimore, Md. This prize is awarded 
for the quickest delivery of both mes- 
sages, and particularly in being on the job 
for the return M.S.G. No one but the 
sending stations east of 9 ZF knew when 
the east bound M.S.G. was coming thru. 
If this had been a real emergency call for 
Government help on 200 meters, these 
same fellows would have landed the mes- 
sage just the same. Congratulations to 
them. 

SECOND PRIZE. 
Mr. W. B. Pope, 4 AA, of Athens, 



Georgia, is awarded the Professional Wave 
Meter, donated by the Electro Importing 
Company of New York. It was awarded 
for long distance reception, prompt busi- 
ness-like delivery, and for perfect index- 
ing, timing and marking both east and 
westbound messages, received in approved 
commercial style. From a study of the 
Q.R.M. map, he was seriously handicapped 
on both messages, and is heartily con- 
gratulated by the writer and all good ra- 
dio "sports." 

THIRD PRIZE. 
Kenneth Briggs of Rochester, N.Y., 8 
MG, whom you all remember as almost 
catching up with C. E. Hughes, the presi- 
dential candidate, with a copy of the Re- 
lay Message on October 27th, 1916, is 
awarded the One K.W. Thordarson Trans- 
former, donated again by the Thordar- 
son Transformer Company of Chicago, 
thru their Mr. Connors. Mr. Briggs is 
congratulated on his persistency, good re- 
ceiving, prompt delivery and true Ameri- 
can spirit, as he showed not the least 
jealousy toward several who were working 
against him. The Q.R.M. map showed 
marked interference, particularly on west- 
bound messages, and he can thank the 
Q.R.T. of W. C. Ballard, Jr., at Cornell 
College, 8 XU, for giving him the chance 
to win this prize. I hope he will perfect 
his sending apparatus, and line up with the 
Q.R.M. League. 

FOURTH PRIZE. 

Scott High School of Toledo, Ohio, is 
awarded the William B. Duck's celebrated 
Arlington Tuner; for long distance recep- 
tion with moderate apparatus ; diligent and 
persistent listening for the return message 
and very complete business-like report. 
FIFTH PRIZE. 

Leander L. Hoyt of Hayward, Cal., 6 SI, 
is awarded the Chambers No. 749 tuner for 
the_ reception of arc and spark signals. 
This prize is awarded for the long distance 
work and incessant effort to line the boys- 
up in that neighborhood to a realization 
that, for once, California would be put on 
the Relay Map. Mr. Hoyt, besides, turned 
in one of the most wonderful and complete 
reports on everything of importance that 
happened, from the moment the westbound 
M.S.G. left New York, until the eastbound 
message arrived in the same city. The ab- 
sence of jealousv shows he is a real man — 
an American — and one from whom we will 
hear more later on. To satisfy you all, we 
will publish this report in this magazine, if 
Mr. Hoyt's permission to do so may be ob- 
tained later. We most earnestly hope Mr. 
Hoyt will not find as much real cause for 
worry when listening in on the wave 
lengths from 6,000 meters up as he heard 
during the relay from 600 meters down. 
California is surely lined up now for good 
work with such 'ellows as 6 EA for send- 
ing L.D. and 6 SI for detail work. Mr. 
Hoyt will make a valuable addition to the 
Q.R.M. League. 

SIXTH PRIZE. 

Mr. and Mrs. C. Candler— 8 NH, whom 
you all know and have heard, are located 
in St. Mary's, Ohio, but their "Sigs." do 
not stay at home. During the Presidential 
Relay, this station received six hard-earned 
credits and later stated that their trans- 
former was not working right. They sure- 
ly proved this during the last relay, as 
their "Sigs." were everywhere, and if it had 
not been for this station, lots of stations 
south and west would never have received 
the Westbound M.S.G. at all. Some who 
did not know 8 NH was supposed to help 
on relay, reported him as Q.R.M. When 
you all get your stations arranged so that 
you can Q.R.M. boys 1,000 miles away, you 
are sure on the trail of efficient long dis- 
tance work. 

This station is awarded the prize of the 



"Geyser" Electric Water Heater 




The Hot Bath is Ready 

Continuous Flow of Water as Desired. Always Ready. 

You only pay for electricity as used. All water that passes through the "Geyser" is 
thoroughly sterilized. The " Geyser" is perfectly insulated and is absolutely safe, no 
danger of short circuiting or electric shock. 

Cold to Hot Water by Merely Turning Handle. 

Both the water and the current act together and both controlled by the movement of 
the faucet handle. To secure hot water turn handle to the left, for cold water turn to 
the right, at the center both the water and current are shut off. 

The Supreme Court has decided that we control the absolute right to the manufacturing of 
"Geyser" Electric Water Heater. Others take warning, as we will prosecute any infringing 
on same. W rite us today to send you full information 

FELDMAN MFG. CO., Inc. 1514 Times Building, New York 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



63 



Perfection Radio Laboratory of Clinton, 
Iowa. One Short Wave Amplifying Tun- 
er. The writer used a tuner of this make 
during the last relay and could hear the 
"Sigs." of 4 CL and 2 PM, very Q.S.A. It 
is a very small and compact affair and am 
sure 8 NH will find it a most valuable ad- 
dition to their station. The owner or mak- 
er of this apparatus calls it a "Cow Suck- 
er." It is the most sensitive and reliable 
receiver the writer has ever used. 

SEVENTH PRIZE. 
O. R. Terry, Stoughton, Wis., is awarded 
the prize of the Manhattan Electric Sup- 
ply Company of Chicago. This is a pair 
of 3,000 Ohm Mesco phones. They are 
dandies, and the writer has been using a 
pair for the last year. Mr. Terry made a 
creditable report and great record for re- 
ceiving thru Q.R.M. of the worst kind. 

EIGHTH PRIZE. 
The Phoenix Radio Club of Phoenix, 
Ariz., is awarded the donation of Mr. 
Philip E. Edelman of St. Paul, Minn. This 
is his latest book, "Experimental Wireless 
Stations," and it is a wonder how so 
much useful information has been crowded 
into such a compact space. This book 
will put Arizona on the wireless map for- 
ever, and the prize is awarded for long 
distance reception, cooperation in the re- 
lay, and real genuine American patriot- 
ism in keeping quiet when necessary. 

INSTRUCTIONS. 
The prize winners may obtain these 
prizes by writing to the above Donees and 
giving your name and address, and refer- 
ring to this issue of The Electrical Ex- 
perimenter. 

Q.R.M. 

There is not enough space in this maga- 
zine to report all Q.R.M., but some of it 
was intentional, and the writer does not 
care to stir up any ill feeling by publish- 
ing it. If you are interested in knowing, 
however, who deliberately Q.R.M.'d the 
stations in Connecticut and Massachusetts 
at 10:35 p.m., the night of February 24, 
1917, write to 1 IZ— R. T. St. James, Great 
Barrington, Mass. 

PERFECT SCORES. 

Below you will find the names of the 
boys and stations that made "perfect scores." 

ARKANSAS. 
John M. Clayton, 5 BV, Little Rock 

ARIZONA. 
R. A. of Arizona, 6 FD, Phoenix 
L. E. Glenn, 6 IT, Alhambra 
J. Giraud, 6 EO, Phoenix 
R. Higgy, 6 DM, Phoenix 

COLORADO. 

E. F. Doig, 9 ZF, Denver 
W. H. Smith, 9 ZF, Denver 

CALIFORNIA. 
Seefred Bros., 6 EA, Los Angeles 
L. Lynde, 6 UG, Long Beach 

C. H. Hirst, Stanford University 

F. Terman, 6 FT, Stanford University 
L. L. Hoyt, 6 SI Hayward 

CONNECTICUT. 
H. Haugh, HH, Derby 

DAKOTAS. 
M. Tuve, MT, Canton, S.D. 
P. C. Green, PG, Aberdeen, S.D. 

D. Cottam, DCL, La Moure, N.D. 

E. Worthington, 9 APG, Aberdeen, S.D. 
E. R. Issak, 9 TZ, Eureka, S.D. 

A. Shaw, AS, Parkston, S.D. 

FLORIDA. 
J. C. Cooper, Jr., Esq., 4 EI, Jacksonville 

C. M. West, U.S.N., St. Augustine 

GEORGIA. 

D. L. Gaston, C\/W, Commerce 
A. F. Hood, CWW, Commerce 



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receive your $7.15 and return the machine to me. I will pay the return / 
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$100.00 for it. It is standard. Over one hundred thousand people own 
and use these typewriters and think them the best ever manufactured. 
The supply at this price is very limited, the price will probably 
be raised when my next advertisement appears, so don't delay. 
Fill in the coupon today — mail to me — the typewriter will be / 
shipped promptly. There is no red tape. I employ no solicitors / 
— no collectors — no chattel mortgage. It is simply understood / 
that I retain title to the machine until the full $40.15 is paid. / 
You cannot lose. It is the greatest typewriter oppor- 
tunity you will ever have. Do not send me one cent. 
Get the coupon in the mails today — sure. 



scribed in this advertise- 
f ment. I will pay you the 
/ $42.00 balance of the 
/ SPECIAL $49.15 purchase 
/ price at the rate of $3.00 
/ per month. The title to re- 
main in you until fully paid 
for. It is understood that I 
have five days in which to ex- 
,■' amine and try the typewriter. 
j If I choose not to keep it, I will 
f carefully repack it and return it 
to the express agent. It is under- 
stood that you give the standard 
guarantee for one year. 



Name 



HARRY A. SMITH 



Address . 



738-231 N. Fifth Avenue 



Chicago 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



6 4 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



A Motor and a Rotor for $5.25 

We have built 5000 of these outfits, consisting of a motor 
that will operate on a. c. or d. c, 5000 to 6000 r. p. m., 100 

to 1 30 volts. 

An aluminum rotor, per- 
fectly balanced, machined 
and insulated. 

$4.00 

Motor only 

$1.50 

Rotor only 
W!-en ordering rotors give size of shaft 

The Fosco Corporation 

1355 N. Western Ave., Chicago, 111. 

Send postage for catalogue of motors and supplies 




Regular price of 
these outfits, $8.50 

Introductory offer 
as above, while 
they last. Act 
quick. 



One-half actual size 



The Mark-o' Quality 

is a storage 
battery 



An Opportunity for Experimenters 

to secure a GOOD storage battery at 
a moderately LOW cost. The 
ONE article you cannoc 
afford to experi- C^* 
ment with CJ^^^ 

vc9 



MARKO 

torage batteries are es- 
pecially adapted for operation of 
all kinds of spark coils, insuring a heavy 
and powerful spark. There is nothing superior 
FOR AUDION USE 



Type 


Volts 


Amp. H.R 


List 


Special price to 




Capacity 


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wireless engineers 


4C2 


4 


40 


$ 7.00 


$4.90 


6C2 


6 


40 


10.00 


7.00 


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60 


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6C6 


6 


80 


16.00 


11.20 



PAUL M. MARKO & CO., Inc., 1191 Bedford Ave., Brooklyn, N.Y. N. Y. Depot— 974 8th Ave., N.Y.City 




New Undamped Wave Coupler No. 749 

Special Introductory Price, $18.00 

Our new coupler No. 749 Is 32" long, 9* wide, and 
10" high, over all, and on an average-sized Antenna 
tunes to 15,000 meters. This coupler, used with the 
new CHAMBERS' SYSTEM or CIR- 
jps CTJJT, will bring in signalslrom domestic 
mm and foreign Arc Stations surprisingly 
#Bi loud and clear. Note the difference in 
size of our No. 748 and No . 749. 
We claim to be the original inventors of 
a SYSTEM or CIRCUIT for the recep- 
tion of the undamped waves without the 
use of Loading Coils or Oscillating Coils, 
as they are sometimes called: as with our 

SYSTEM or CIRCUIT only two Inductively 
Coupled Coils are necessary. Circuit supplied 
with each coupler. 

This CHAMBERS' CIRCUIT saves you money, 
o pay for. and price of coupler only $18.00. Place order 
introductory price. Orders tilled in rotation. Send for 

F. B. CHAMBERS & CO., 2046 Arch St., Phila., Pa. 



_ THERE'S MONEY IN IT** 

T..ZT1MORSE AND WIRELESS"." JHZ* 



LEARN TELEGRAPHY^Sf^*' 




TEACH YOURSELF 



in half the usual time, at trifling cost, with the 
wonderful Automatic Transmitter, THE 0MNIGRAPH. 

Sends unlimited Morse or Continental messages, at 
any speed, just as an expert operator would. 

Adopted by U. S. Gov't. 4 stylet. Catalogue tree. 

OMNIGRAPH MFG. CO. 

39L Cortlandt St. New York 



C. H. Williams, 4 CY, Covington 
J. R. Shumate, 4 EC, Tomasville 
W. B. Pope, 4 AA, Athens 
INDIANA. 

G. Decker, 9 QNO, Ligonier 
L. B. Wilcox, 9 KH, Angola 
L. Gehring, 9 AAS, Bluffton 

P. K. Romey, 9 QR, Columbia City 
J. E. Williams, JW, La Grange 

ILLINOIS. 
S. W. Pierson, 9 PY, Carrolton 
R. H. G. Mathews, 9 ZN, Chicago 
E. E. Boynton, 9 ARA, Sycamore 
L. A. Kern, 9 GY, Matoon 

H. Klaus, HK, Eureka 

R. W. Beard, 9.GK, Pleasant Plains 
E. H. Giddings, 9 MK, Lanark 
H. A. Mackley, 9 AIM, Peoria 
IOWA. 

W. E. Slauson, 9 AMI, Monticello 
H. O. Ainsworth, 9 AMI, Monticello 
S. U. of Iowa, 9 YA, Iowa City 
Don Bailey, 9 RD, Clinton 
Lester Fawcett, 9 AIF, Independence 

C. Tumwall, CT, Ottumwa 
W. Harper, WH, Ottumwa 
H. M. Ennis, HME, Ottumwa 
Kent Bros., 9 ARF, De Witt 

"The Old War Horse," 9 RD, Clinton 

KANSAS. 
W. S. Ezell, 9 YE, Wichita 
Karl Keller, 9 ADE, Kinsley 
LOUISIANA. 
P. E. Grenlaw, 5 BB, Franklinton 

MASSACHUSETTS. 
R. T. St. James, 1 IZ, Great Barrington 
P. C. Smith, Haverhill 
E. B. George, 1 ANA, Framingham 
B. H. Moran, 1 AAM, Natick 
MINNESOTA. 
Peter Hansen, PH, Chisolm 
MICHIGAN. 
J. L. Munger, LM, Sturgis 
W. Benson, 8 ANR, Battle Creek 
Ed. Holby, 9 OE, Marquette 
Y.M.C.A., 8 QJ, Ann Arbor 
M. B. Rann, 8 ADR, Lansing 
W. Koivanen, WK, Chisolm 

D. G. Carter, 8 WR, Grosse Point 

MISSOURI. 
W. Corwin, 9 ABD, Jefferson City 
Washington University, 9 XV, St. Louis 
H. Longmire, Monroe City 

B. Emerson, Monroe City 

MARYLAND. 

C. E. King, 3 SV, Baltimore 

E. B. Duvall, 3 AK, Baltimore 
A. P. Smith, 3 AK, Baltimore 

L. W. Passano, Marconi Operator, M. & 
M. Co., Baltimore 

MONTANA. 
A. C. Campbell, 7 ZC, Lewiston 

NEBRASKA. 
Bradford Telepea, No Call, Tekomah 

NEW YORK. 
J. N. S impson, 8 CM, Rochester 
W. C. Ballard, 8 XU, Ithaca 
Genesee Radio Station, 8 OZ, Rochester 
Dr. H. E. Fitch, 8 ZE, Elmira 
O. W. Saxton, 8 FY, Buffalo 
A. C. Young, 8 ARB, Buffalo 
H. Blower, 2 HB, Brooklyn 
Kenneth Briggs, 8 MG, Rochester 
J. Weiss, 2 FH, Port Washington 
G. M. Benas, 8 CC, Utica 
W. J. Vickery, 8 SE, Gloversville 
J. K. Hewitt, 2 AGJ, Albany 

NORTH CAROLINA. 
W. S. Rothrock, 4 DI, Winston Salem 
J. T. Moorehead, JM, Greensboro 

OHIO. 
Fred Travis, Defiance 
R. Hoffman, Defiance 

D. Israel, 8 ANC, Cincinnati 
G. D. Howsare, 8 ASG, Eaton 

(The balance will be publisht in the June issue.) 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



65 



Are You An American? 



Are you with the country or against it? 
If you own a radio outfit it behooves you 
as a patriotic American to offer your Wire- 
less Station to your country. You do not 
obligate yourself in any way by signing the 
blank printed below, except that you give 
the Government permission to operate your 
station at any time its officials may see fit 
to use it. 

Thousands of Amateurs have thus 



pledged their stations, WHY NOT YOU? 
Sign the blank tb-day, and it will be prompt- 
ly forwarded to Washington. ( See also 
page 3, this issue.) Join the Radio League 
of America; no fees, no dues to be paid. 
By joining you get a free membership cer- 
tificate printed in green and gold. Send 
stamp for large eight page information 
booklet. Radio League of America, 233 
Fulton Street, New York City. 



■ nit 111 ■ 1 111 j iikiiic^ iiifiiiiiiiiisiiiiii iicr^iiiii 1 1 iiicsitiiciiiiniii iiiiiiiiriiiicjiiiiiiii 11 inita 111 ruin 

Application for Membership in the 

Radio League of America j 

I "Kt THE UNDERSIGNED, a Radio Amateur, am the owner of a Wireless | 

I /II Station described in full on the face of this application. My station = 

§ has been in use since , and I herewith de- § 

I sire to apply for membership in the RADIO LEAGUE OF AMERICA. | 

I I have read all the rules of the LEAGUE, and I hereby give my word of | 

5 honor to abide by all the rules, and I particularly pledge my station to the 5 

5 United States Government in the event of war, if such occasion should E 

3 arise. p 

i I understand that this blank with my signature will be sent to the = 

§ United States Government officials at Washington, who will make a record i 

I of my station. = 

E Witnesses to signature: Name H 

I City I 

I State I 

I Date 191 | 

E Describe the apparatus of your station on the blank below. e 

I In the event of national peril, you will volunteer your services as a E 

^ radio operator in the interest of the U. S. Government? = 

I This last question need not be answered unless you so desire it. | 

I Description of My Station and Apparatus | 

i Sending E 

§ Receiving E 

I (5-17) I 

P.iiiiiiiiiiiiiiiiiinimiiiiiiinc: iiiiiiiiiiiiiiiiiiiMiiiiicaiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiEaiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiicaiiiiiiiiiniiiiiiiiiiiiiiiiiiiiiEaiiiiiiiiiiiiiiiiiiiiiiiiiiii^ 

CUT OUT, FILL IN, AND RETURN AT ONCE 



DISTRIBUTED CAPACITY AND ITS 
EFFECT. 

(Continued from page 33) 

of the June 1916 issue of this journal. For 
those who have not seen this copy, the 
accompanying reproduction is made, Fig. 5. 
The construction is very simple and the 
drawing is self-explanatory. 

The effect of distributed capacity and 
dead-end effect is more pronounced in long 
coils and it is advisable to wind such coils 
in sections as shown in Fig. 6. It has been 
found that a considerable amount of dis- 
tributed capacity is eliminated by such a 



method of winding and it should be done 
in every case where it is possible, especially 
on secondaries of loose couplers. The 
reason for reducing the distributed capac- 
ity is self-apparent, as the capacity varies 
inversely as the thickness of the dielectric 
between the conducting mediums. Thus the 
capacity is reduced by increasing the dis- 
tance between sections. It will be an ideal 
inductance if each turn of the coil is sepa- 
rated from its neighboring turn, say, one- 
thirty-second of an inch each. The distri- 
buted capacity of such a coil would be very 
small as compared to a coil with the wires 
close together. 




" You Get The Job" 

"We've been watching you, 
young man. We know you're 
made of the stuff that wins. The 
man that cares enough about his 
future to study an I. C. S. course 
in his spare time is the kind we 
want in this firm's responsible 
positions. You're getting your 
promotion on what you know, and 
I wish we had more like you." 

The boss can't take chances. 
When he has a responsible job to 
fill, he picks a man, trained to hold 
it. He's watching you now, hop- 
ing you'll be ready when the op- 
portunity comes. 

The thing for you to do is to 
start today and train yourself to do 
some one thing better than others. 
You can do it in spare time 
through the International Corre- 
spondence Schools. Over 5000 men 
reported advancement last year as 
a result of their I. C. S. training. 

The first step these men took 
was to mark and mail this 
coupon. Make your start the 
same way— and make it right now. 

I. C. S., Box 53 4 6, Scranton, Pa. 
nNTERNATSONALloRRlsPONDENCE SCHOOLS 

Box 534 6, SCRANTON. PA. 

Explain, without obligating me, how I can qualify for 
the position, or in the subject, before which I mark X. 



□ ELECTRICAL ENGINEER 

□ Electric Lighting 

_j Electric Car Running 

□ Electric Wiring 

□ Practical Telephony 
J Telegraph Expert 
^MECHANICAL ENGINEER 

□ Mechanical Draftsman 

H Machine Shop Practice 
Gas Engineer 

□ CIVIL ENGINEER 

□ Surveying and Mapping 

□ MINE KOKEM'N OR ENG'ft 

□ Metallurgist or Prospector 

□ STATIONARY ENGINEER 

□ Marine Engineer 

□ ARCHITECT 

□ Contractor and Builder 

□ Areliiteetural Draftsman 

□ Concrete Builder 

□ Structural Engineer 

□ PLUMBING AND HEATING 

□ Sheet Metal Worker 

□ CHEMICAL ENGINEER 

Name 



B SALESMANSHIP 
ADVERTISING MAN 

□ Window Trimmer 

□ Show Card Writer 

□ Outdoor Sign Painter 

□ RAILROADER 

□ ILLUSTRATOR 

□ DESIGNER 

□ BOOKKEEPER 

□ Stenographer and Typist 

□ Cert. Pub. Accountant 

□ Railway Accountant 

□ Commercial Law 

□ GOOD ENGLISH 

□ Teacher 

□ Common School SnbJecU 

□ CIVIL SERVICE 

□ Railway Mail Clerk 

□ AGRICULTURE 

□ Textile OverBeer or Snpt. 

□ Navigator □ Spanum 

□ Poultry Raising H German 

□ AUTOMOBILES Q French 

□ Auto Repairing □Italian 



Occupation 
& Employer. 



Street 
and No.. 



City . 



. State_ 



If aanje of Course you want is not ia this list, wrile it below. 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



66 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



for Your Home 

The Uni*Lectric is a complete electric 
service station in home size. Generates 
standard 110-volt direct current. Biff ca» 
pacity--ope rates one to 50 lights* electric 
motors up tol h. p., electric irons, electric 
heaters, vacuum cleaners, force pumps, 
chums, separators, washing- machines, etc.— 
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wish. Uses standard lamps and fixtures. 

No Belts-No Batteries 

Oar patented, high-speed, rotary alcove valve engine 
operates the modern, high-speed generator with such 
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one small compact unit, ready for quick Installation. 
Simple, dependable and economical. The entire outfit 
guaranteed for five years. Write today for free copy of 
our new catalog on farm lighting plants. 

\ Waterman Motor Company 

§, 112 Mt Elliott Ave. Detroit, Mich. 



The orJy home size 
. lighting plant that 
\ operates toithout 
X storage batter- 
ies. 



*f CASOUME-KLEC'TWC UNIT 

LIGHTING SYSTEM 





-21- 

Jewel Elgin, Waltham, Howard, 

y watch you waot, seud for 



J pages of wonderful values, d*Ia« 
^monds, watches, rings, jewelry, up- 
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r r you will never misa the money. Get 
"posted, write today. 

ALFRED WARE CO., Dept. 705 St. Lonis. Mo. 



AC ORN UN I-LITE 

FREE 




Turns ni^ht into day. 
300 candle power. 
Carry as a lantern; use 
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motorists. Agents make bio money. 
Write tonight for new 191/ offer. 
ACORN BRASS MFG. CO., 22Um-L.le 8ldg., Chicane 



TYPEWRITERS 




$10 and Up All Makes Save $25 to $50 

on rebuilt at the factory by the well- 
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cash — installment or rented. Rental 
applies on purchase price. Write for 
lull details and guarantee. Free trial. 

Young Typewriter Co., Dept. 176, Chicago 



ELECTRICITY 



I can teach you by practical work the Electrical 
profession in your own home. Short time required 
and easy payments. MATERIAL and TOOLS 
FREE. Write me to day for free book on Electricity. 

L. L. COOKE, Dept 21 

439 Cass Street CHICAGO, ILL. 




200 and You Cet Th!s 
= Superb Cornet 



An astounding offer. Pay the balance at 
the rate of 10c a day. Free trial before 
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WLlDL.tlZEl> FREE Band Catalog! 

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the U. S. Gov't. Write today. 

THE RUDOLPH WI>RL-ITZER CO. 
Cincinnati^ ^^f f t 74*5 Chicago. Ill 



Free Carrying Case 

with this Superb 
Triple Silver Plated 
lyric cornet, genuine 
^eatiierjWrite^oday^ 



EDDY CURRENTS. 

{Continued from page 21) 
as one of the fleet when the war had 
broken out. I tried to ask him questions, 
but he was as clammy as Parker and I 
could get nothing out of him. 

What was behind that locked steel door? 
Was the means of destroying the enemy's 
ships concealed there? What was this 
curious torpedoless means? I wanted to 
ask Parker, but pride and shame at my 
own stupidity held me back. So I won- 
dered and pondered and puzzled all that 
day. 

Thought of the affair was dispelled when 
about sundown the lookout sighted an 
enemy aeroplane dead ahead and some dis- 
tance aloft. We immediately sank to the 
awash condition and then as the plane 
grew near, we submerged with only our 
periscope showing. This we drew in as 
we noted that the aeroplane sighted us 
and swooped down for a look. We ran 
submerged for a half hour or so and then 
cautiously poked up our periscope. 

There was a sudden cry of warning from 
the man at the instrument and we dove 
again. There had been an enemy torpedo 
boat destroper near, and even in the dusk 
it was not safe to come up when any of 
these craft were about. We had been 
sighted we knew, for its searchlights made 
the water dimly translucent above us. 
But we submerged below the light and ran 
still east by north. 

It was just after this that I noticed that 
Billy came to the feeler case. I heard 
him give directions that the small alterna- 
tor which supplied the coil with current, 
should be started. Then he worked the two 
control wheels, and by glancing over his 
shoulder at the dials I saw that he was 
sweeping the coil from side to side, and 
frequently changing its inclination. By 
this means he was throwing out an arm 
of magnetic force which would indicate the 
position of any enemy ship within ten 
thousand yards. 

"Hunting for fish?" I asked. 

"Yes, I'm feeling for them," he an- 
swered, watching the angle of the hori- 
zontal gage, and then turning to me with 
a twinkle in his eye. "Have you solved 
it yet?" 

"No, I haven't," I admitted. 

"You watch tonight then," he said. 
"We're about due to be in the enemy's 
fleet and we ought to have some experience 
at least." 

The light on the case before him flashed 
suddenly red, and the dial needle marking 
distance jumped up to eight thousand and 
stopt there. He turned and held the hori- 
zontal control wheel stationary a mo- 
ment. 

"We're in them now," he said. "There's 
the first one." 

There followed a most wonderful piece 
of maneuvering. He turned the coil until 
he was sure of the position of the enemy, 
and then changed the course of our boat 
to correspond to his. Slowly we worked 
around, the little coil giving us the posi- 
tion of our foe with its unerring magnetic 
touch. 

In half an hour we were making twenty- 
two knots west by south and running thirty 
feet under. The enemy was off to star- 
board according to our indicator. 

"He must be a battleship. Twenty-two 
is too slow for anything else," Billy said. 

I agreed and a moment later, with a 
final assurance that our courses were 
parallel, Billy turned to a locked case be- 
side the feeler box. I glanced at the dial. 
The enemy was just 1436 yards away ac- 
cording to our readings. 

Billy was opening the case which looked 
exactly similar to the feeler, but lacked 
the lamp and distance dial and had only 



two control wheels. Under it was a small 
electric pushbutton whose function I 
could not understand. 

He twisted the control wheels for a 
moment until the dials read the same as 
those of the feeler. Then he called down 
the speaking tube. 

"Start the alternator." 

"Yes, sir," came back Dickenson's reply. 

I heard faintly above the other ma- 
chinery the starting crescendo of a turbine. 

"Here goes for a trial," Billy said. 

I watched him, and with a final glance 
to make sure that both dials corresponded, 
he deprest the button. The machine for- 
ward, the alternator, I thought, dipt sev- 
eral notes in its hum and then rallied. The 
button was down for four or five minutes 
and then he let it up and gave the com- 
mand to stop the alternator. 

What had he done? Had this deprest 
button let loose some mysterious new force, 
some wonderful ray, some hitherto un- 
discovered etherial vibrations which could 
travel through water and destroy the enemy 
ship alongside us? What had he done when 
he prest that button? I wanted to ask 
him, but again pride and chagrin stopt 
me. 

Instead I went to my instruments, think- 
ing that I might pick up some of the 
enemy's talk and hear something worth 
knowing. To this purpose I juggled my 
tuner knobs, getting many and rapidly 
changing combinations with the sliding 
contacts. 

It was while doing this that I heard a 
sudden loud buzz in the receiver. I held 
the adjustment there a moment and heard 
several letters, apparently forming a for- 
eign word. Then I listened while a mes- 
sage in the enemy's tongue was spelled 
off loudly into my receiver. I wrote it 
down as it came. When it had stopt and 
I had translated it, I had before me the 
following : 

"The fire in the forward port compart- 
ment, No. 7, is in the oil tanks and is so 
hot that it has melted out a section of the 
hull plates. We have a heavy list to port, 
but are not in immediate danger. Good 
luck. 

"Captain Von Heissburg, 

"The Stoltzenfels." 

That looked as if there was trouble in 
one of the enemy's ships. I showed the 
message to Billy. 

He read it over twice and then glanced 
up with a gratified light in his face. 

"Pretty good, but not quite enough," he 
said. "Have to use more next time I 
guess," and he turned away to the feeler 
case. 

I could make nothing of this remark 
and did not try to. I was too busy watch- 
ing him again. 

Once more he was sweeping with the 
feeler. We were bearing off to the south 
and running slowly. Again the light 
flashed and he twisted controls and helm 
until we ran parallel with the enemy. 43 
yards away and off his starboard side. 
Once again we were thirty feet under and 
running at twenty-two knots, which seemed 
to be the speed of the fleet. As before 
Billy twisted the controls on the other and 
un-named case until the dials read the same 
as the feeler. Once again he called the 
order to start the alternator. The hum of 
the machine sounded and as before the 
button was prest. I timed it now and 
found that it was held down six and a 
half minutes. 

Then we sheered off to the south, slow- 
ing up and letting the enemy pass ahead 
of us. 

I watched again in intense but unsatis- 
fied curiosity while Billy twisted and 
and turned the little wheels and after our 
boat came parallel to the enemy, prest the 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



67 



button after having the alternator started. 

Fourteen more times it happened that 
night, while we maneuvered and changed 
our course to get into position. I did not 
get a chance to ask him that night. He 
was busy and the gratified light was too 
strong in his face, and I knew from all 
signs that I would only encounter more 
teasing. 

So I stood by and watched and wondered 
what mysterious force was being loosed 
when he prest that button. Was ii inten- 
sified wireless waves? I listened at my 
receivers once to make sure of this theory, 
but heard nothing. So I gave it up and 
watched and waited to let him tell me in 
his own way at his own time. 

The next morning we had cruised foi 
two hours without catching anything in the 
meshes of our magnetic net and Billy was 
about to give the order to come to the sur- 
face when we picked up something off our 
port bow. We slowed down to fall in with 
it, since it seemed to be running slower 
than we. After a few moments we found 
that it was stationary. We ran around it 
three times and then running several hun- 
dred yards away from it, Billy gave the 
order to come up cautiously. 

The rising periscope flasht the picture, 
the scene that was there, spread on the 
water in the early morning light. I saw 
it over Billy's shoulder in the mirror. 

It was a proud battleship, or had been, 
now leaning far over to port and sur- 
rounded by a bevy of small boats filled to 
overflowing with men. The great guns 
were pointing wryly skyward, and gave it a 
ridiculously helpless air as it lay there, 
rolling heavily in the swell of the «ea. 

"Its the Stoltzenfels," Billy said, look- 
ing intently into the mirror. 

Then I remembered the message from 
her captain which I had overheard last 
night. I was about to mention this when 
I saw that the men in the boats had 
sighted us and were now pointing to us 
and signaling to the battleship. One of 
the great turrets swung about drunkenly 
and then we dove. We ran under the ship 
and her boats and then away to the west. 

"Let them go. They can't hurt anything 
with that leaky tub. That's the one we 
experimented on and didn't give enough 
to," Billy said. 

We ran that morning with our periscope 
and breather pipes out of water, but ready 
to sink unseen if necessary. We saw noth- 
ing of the enemy, but about nine o'clock 
while at the receivers I caught this mes- 
sage : 

"Captain Rollins, U.S.X. Aviation Corps. 
Have sighted much wreckage and hun- 
dreds of enemy boats filled with men. Also 
life rafts and other floating objects with 
men clinging to them. Sighted the Stolt- 
zenfels leaking badly, and with many boats. 
Caught glimpse of few transports but kept 
away by destroyers. Send cruisers and de- 
troyers out at once. Battleships seem 
lost. Lieutenant Fletcher, Aviation Corps 
No. 7." 

This I knew came from the wireless of 
one of our big scoutplanes which had been 
sent out to watch the movements of the 
enemy fleet. 

I showed it to' Billy Parker. He read 
it and his face lit with satisfaction in spite 
of the fatigue of the sleepless night. 

"Good," he shouted, "we got them all 
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daring to broach this subject again in the 
face of his good humor. 



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"You poor stupid blockhead," he 
laughed, slapping me on the back, "don't 
you see yet?" 

"No, I don't see at all," I admitted. 

"Let me tell you so you can wireless the 
whole thing back to the papers. You 
understand how that feeler works?" 

"Yes, perfectly," I said. 

"Well, up on the bow we have a big coil 
just like that, mounted on a universal joint 
so it can be raised or lowered or swung 
around at any angle in the vertical or hori- 
zontal, except directly back. That coil takes 
about two thousand kilowatts of current 
which is supplied to it by a big alternator 
put in the old torpedo room forward." 

He paused. 

"Well?" I demanded. 

"Don't you see now?" he asked. 

"No, I don't, go on," I commanded. 

"Oh, man, you haven't a bit of imagina- 
tion," he groaned. 

"Well, we can swing this coil around 
and send a current thru it," he went on. 
"If an enemy ship comes within one hun- 
dred yards of us, the same thing will hap- 
pen that happens in an induction furnace. 
We can send enough eddy currents thru 
his hull to melt out a whole section of the 
plates. Now do you understand?" 

But I was at the key, pounding out the 
message. 



COMBATING THE TORPEDO. 

(Continued from page 11) 

hand on Detonator switch No. 1, he calm- 
ly waits. When the hostile torpedo is but 
ten feet distant from motor torpedo* No. 1, 
he throws the switch. There is a terrific 
explosion and a huge column of water is 
thrown up several hundred feet into the air. 
Motor torpedo No. 1 has vanished, so has 
the enemy torpedo. The ship for the time 
being is safe. Instantly the crew has low- 
ered away a new motor torpedo to take 
the place of the one just destroyed and 
long before it touches the water it has been 
electrically connected to the control board. 
But this would be necessary only for a 
large ship with a very valuable cargo. A 
small steamer would have enough torpedoes 
left to cope with the enemy. By this time, 
too, enough time has elapsed for the ship 
to alter its course and run in a zig-zag 
line, making it very difficult for a subma- 
rine commander to hit the fleeing vessel 
with the next torpedo. But in case of 
necessity the other motor torpedoes are 
still "in the ring" to successfully grapple 
with the enemy. Even where two torpe- 
does are sent simultaneously against the 
ship the scheme will work out satisfactori- 
ly. In that case the operator at the con- 
trol-board simply has to work two rheo- 
stats and two detonator switches instead of 
one and given a level head and a good eye 
for calculating distances and speeds, the 
task is not such a very difficult one. 

There are a number of firing positions 
and schemes and while as a rule only one 
motor torpedo would be used to destroy the 
enemy torpedo, Fig. 1 shows how two mo- 
tor torpedoes could be brought close to- 
gether (see dotted lines of No. 1) to inter- 
cept the deadly missile. In that case torpe- 
does No. 1 and No. 2 would be freed si- 
multaneously and leave little chance for the 
enemy torpedo to escape. 

It is, however, not always absolutely 
necessary to actually destroy the hostile 
torpedo. Suppose that the submarine fires 
from a close range, and suppose that the 
selected motor torpedo cannot be speeded 
up fast enough — even by overloading its 
motor 100 per cent by raising its voltage 
— to come closer to the enemy torpedo 
than, say, thirty feet. Even in such an 
extreme case — tho quite possible in rough 
weather — the control operator fires his tor- 
(Continued on page 70) 




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May, 1917 



THE ELECTRICAL EXPERIMENTER 



69 




Edited by H. GERNSBACK 

In this Department we publish such matter as is of interest to inventors and 
particularly to those who are in doubt as to certain Patent Phases. Regular in- 
quiries addrest to "Patent Advice" cannot be answered by mail free of charge. 
Such inquiries are publisht here for the benefit of all readers. If the idea is 
thought to be of importance, we make it a rule not to divulge details, in order to 
protect the inventor as far as it is possible to do so. 

Should advice be desired by mail a nominal charge of $1.00 is made for each 
question. Sketches and descriptions must be clear and explicit. Only one side of 
sheet should be written on. 



SAFETY-FIRST OIL CAN. 

(144.) John Brent Marshall, Cincinnati, 
Ohio, submits drawing and description of a, 
what he calls, safety-first oil can, and wants 
to know if it can be patented. 

Ans. The idea as submitted contains 
nothing new to our mind and we are quite 
positive that no patent can be obtained on it. 

LIGHT DIMMER. 

(145.) Arthur Norris, Defiance. Ohio, has 
submitted a light dimmer which acts on the 
principle based upon the rotary potentiome- 
ter, the idea being to place a high resistance 
between supply wires and the light. 

Ans. This is a very good idea and we 
are quite certain that the device can be pat- 
ented. We have never seen anything like 
it on the market and providing the device 
can be made cheap enough and incorporated 
in a lamp socket, there should exist a good 
demand for same. We would advise our 
correspondent to get in touch with a patent 
attorney at once. 

SPARK PLUG. 

(146.) Clarence Melotz, Florence, Neb., 
submits what he calls a sootproof spark 
plug. The arrangement is such that the 
spark is supposed to keep a small cup from 
carrying carbon. Our advice is asked. 

Ans. There does not seem to be anything 
new contained in this and at the present 
time there is a very similar spark plug on 
the market under the trade name of the 
"Soot-proof" spark plug. 

PROPELLER. 

(147.) Alison J. Kurth, Colorado Springs, 
Col., encloses sketch and description of a 
propeller for motor-driven boats. Instead 
of using a propeller, a certain perforated 
disc is used and our correspondent would 
like to know if we advise him to have it 
patented. 

Ans. While this propeller no doubt works, 
it is impossible to determine its efficiency 
without actually testing it out, in practice. 
It is very doubtful to our mind, however, if 
this propeller should be more efficient than 
the regular one. In the absence of actual 
tests, we would not like to finally commit 
ourselves and advise our correspondent to 
try out the device in practice before apply- 
ing for patent. 

AUTOMATIC VOICE RECORDER. 

(148.) Joseph Prochaska, Chicago, 111., 
submits to us drawings and specifications 
of a novel idea, particularly for use by 
physicians whereby it is possible for a 
patient to call up the doctor while he is 
not at home and instead of the doctor 
answering, the phonograph does this for 
him, all automatically, telling the patient 
where the doctor can be located or when 
he will return. 

Ans. The device is well worked out and 
while there does not exist an urgent de- 
mand for this invention, there is no doubt 
quite a number of people who would be 



interested in owning such an apparatus. We 
think a patent might be obtained upon the 
mechanical features embodied in this device. 



"PERPETUAL MOTION." 

(149.) Percy Muirhead, Dayton, Wash., 
submits a scheme of "Perpetual Motion" in 
which is utilized a Radiometer which as 
.is known, works by light striking it. He 
wants our opinion of this scheme. 

Ans. There is no such thing as "Per- 
petual Motion" and by using a Radiometer, 
this rule is no exception, for the simple 
reason that the Radiometer employs light 
which is a form of energy, and for this 
reason the scheme cannot be termed "Per- 
petual Motion" and no patent could be ob- 
tained on the idea. 



WINDOW ATTRACTION. 

(150.) L. E. Summerton, Maryville. 
Tenn., has submitted to us a window at- 
traction and he vould like to know if it is 
worth while patenting. Also if there is 
a ready sale for such a device. The idea 
consists of an electrical arrangement where- 
by a small artificial bird acts as a wood- 
pecker, pecking against a piece of wood 
every few seconds. 

Ans. This is a very good idea and by 
elaborating it a little more, we are quite 
certain there would be a good market for 
a thing of this sort. By using a plurality 
of birds, a very interesting window attrac- 
tion would be had. 



WAVE MOTOR. 

(151.) C. Mattison, Oakland, Calif., sub- 
mits drawing and description of a wave 
motor to be used in the ocean to utilize 
the power of the waves. He wants to 
know what we think of it and whether it 
is practical. 

Ans. _ There is nothing new contained 
in the idea, which is not a good way of 
solving the problem. The first requisite 
necessary for a good wave motor is that 
it must automatically adjust itself to the 
• various water levels as the tide rises or 
falls. Such an idea was shown in our 
February issue from which it will be read- 
ily seen that the device will of necessity 
have to be somewhat complicated for best 
results. 




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THE ELECTRICAL EXPERIMENTER 



May, 1917 



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COMBATING THE TORPEDO. 

{Continued from page 68) 
pedo anyway. The result is such a terrific 
as well as instant disturbance in the water 
that the enemy torpedo will be certainly 
deflected sufficiently from its original course 
so as to make it ineffective. And after all, 
this is what we want. For the enemy tor- 
pedo once it is spent, sinks automatically, 
because to leave it roam about the sea 
would constitute as much danger to its 
own submarine as to the attackt vessel. 

All the technical points have been 
worked out satisfactorily and while the 
basic idea can and will be no doubt im- 
proved upon, the reader can form his own 
opinion as to the practicability and effect- 
iveness of the scheme. 

The main point in its favor is that each 
torpedo can be built at a cost of less than 
$1,000. For ten units this makes a cost of 
less than $10,000 for a ship of 600 feet. 
This is pretty cheap insurance, consider- 
ing that the cargo alone on such a ship 
nearly always is worth from three-quar- 
ters to one million dollars and often con- 
siderably more. The ship itself costs as 
much again. Besides if the vessel is pro- 
tected adequately, the maritime insurance 
is reduced largely and no big bonuses need 
be paid to the crew, as is the case now. 

The speed of the ship is not reduced by 
the motor torpedoes either, as. they run in- 
dependently, nor is the power to operate 
them very great. For ten torpedoes we 
require but 100 to 150 horse-power — a 
trifling amount for a 600-foot steamer de- 
veloping some 20,000 to 30,000 horse-power. 

Nor are the motor torpedoes used dur- 
ing the entire trip. Thus during a cloudy, 
dark night, during a fog, or in a very heavy 
sea there is no need for them, as a sub- 
marine cannot successfully torpedo a ship 
in such cases. 

During these periods the motor torpe- 
does are hoisted out of the water by means 
of their steel covered cables and are lashed 
fast to the decks till needed. 

As the torpedoes are fired by electricity, 
there is little danger from an accidental 
explosion, even if they should bump against 
the side of the ship occasionally, for in- 
stance during launching or in a squall. The 
distance of 50 feet of the motor, torpedoes 
from the mother ship is necessary, for if 
they are exploded at a closer range than 
30 feet they will damage the ship. 

That the submarine commander sees the 
brightly colored torpedoes does not matter 
in the least. For he will soon learn that 
firing torpedoes at a ship thus protected 
is a waste of time and material. And then 
until something better is found, submarine 
warfare, to a large extent, will sink into 
a stalemate. And this is what we all desire. 

A ship equipt with guns (to prevent the 
submarine from using its own guns) and 
equipt with motor-torpedoes as well stands 
little chance of being sunk. 

It should be noted that our cover design 
is not strictly correct. First, the motor-tor- 
pedoes in practise run almost entirely sub- 
merged, leaving only part of the mast ex- 
posed. Secondly, the submarine is shown 
very much too close to the ship. These 
slight technically incorrect points were nec- 
essary to bring out the idea from an ar- 
tistic standpoint. , 

GLADSTONE AND THE TELE- 
PHONE. 

The mental fatigue which would follow 
the introduction of the telephone was fore- 
seen by the late Mr. Gladstone, England's 
grand old man. When he was asked by 
Mr. Edison's representative whether he 
would like to have a telephone apparatus 
set up in his house, he wrote on a post- 
card : "Sir, my means of communication 
from without inwards are already equal to 
my needs and in excess of my desires." 



MAGNETISM PRODUCES RE- 
MARKABLE PHOTOGRAPHS. 

{Continued from page 14) 

like a line of latitude, no mere arrange- 
ment of the molecules of a magnet, can 
account for the result. There must be 
motion — currents of ether, for there is only 
ether under the receiver. 

A detailed examination of the articles 
will strenghten this proof. The articles are 
lettered somewhat in the order in which 
the impression is made on the plate. Note 
that at A, but little, if any, impression is 
made on the plate — the currents could not 
penetrate — while J and K hardly show at 
all because the currents past thru them 
and affected the plate; and to pass thru 
or to penetrate there must be motion — 
currents. From A to K, it will be noted 
that the effect on the plate grows gradually 
stronger, showing that some are more pene- 
tratable than others and this degree of 
penetration implies motion. Note that D, 
E and F are penetrated less than G, and 
that G is penetrated irregularly, plainly 
showing the location of the acid pits on the 
surface of the zinc. None of these effects 
could be produced by light. Again, B and 
C are iron weights with cavities in the bot- 
toms and openings thru the sides of these 
cavities. The weights were placed on the 
plates so that the cavities were downward. 
Yet these cavities show plainly in the plate. 
Light could not produce this effect, for in 
any event it would produce a shadow and 
enough light could not enter the small open- 
ing to effect the plate practically as much 
as the exterior. But currents of ether fol- 
lowing the lines of the iron, as is the well 
known effect of iron in a magnetic field, 
could and did produce this result. More- 
over, careful measurements show that the 
cavities are a little larger and the circum- 
ferences of the weights as shown in the 
plates are a little less, than in the weights 
themselves, conforming to the well known 
deflection or bending of lines in a magnetic 
field by the presence of iron. But the 
crowning proof is in H. Here is a wooden 
button showing the grain of the wood. The 
wood was penetrated more in some parts 
than in others. Light could not produce 
this effect for it could not penetrate the 
wood and if it were supposedly possible to 
bring to bear light strong enough to pene- 
trate the button, it would penetrate all 
parts equally. The cracks and seams in 
J and K are shown in the same manner but 
in a less degree. Here then is unques- 
tionably penetration, and penetration can 
not possibly take place without motion. 
Who would now question the existence of 
currents about the magnet? 

Furthermore, here is incontestable proof 
that the lines of force, lines of tension, 
mere lines of direction do not "emerge 
from" (without motion) the North pole of 
the magnet, nor "pass to or enter" (again 
without motion), the South pole. The 
effect, the penetration, the currents are 
equal over both poles. These currents pass 
into both poles alike. They do not pass 
out from the poles for the plate is above 
the poles, both poles, with the sensitive 
side upward, and the objects are on the 
sensitive side of the plate above the poles. 
If the currents were passing upward from 
either pole, there would be no impression 
on the plate over that pole, for the current 
would oass thru the sensitive film before 
reaching the objects. Instead, it shows 
plainlv that the currents past poleward 
equally over both poles, penetrated more or 
less the objects on tne plate, affected the 
sensitive plate more or less according to 



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May, 1917 



THE ELECTRICAL EXPERIMENTER 



7i 



the amount of penetration, and then past 
on to the magnet. What then becomes of 
them will be shown later. 

Still there are doubters. Could the re- 
sult be due to stray light? Could it be 
due to phosphorescence? To radio-activ- 
ity? Could the same result be obtained 
without the magnet? To answer these I 
placed a plate over a wooden "U" under 
the receiver, with the objects placed updn it 
exactly as before and used exactly the same 
precautions as in the first instance. At 
the same time and in the same room, far 
enough away not to effect the plate under 
the receiver, I placed a plate over the mag- 
net with several objects upon it, but with- 
out a receiver, placed a light-tight box over 
this, and covered the whole with heavy 
folds of black cloth. In this instance the 
room was not opened for twenty-two days. 
At the end of that time both plates were 
developed with equal care under the same 
conditions as in the first case. The plate 
over the wooden support under the re- 
ceiver was a perfect blank! There was no 
impression on it. The result with the plate 
over the magnet in the air is shown in 
Fig. 4. In this A is a key, B and C are 
pearl buttons, and D, E and F are wooden 
buttons. The grain of the wooden but- 
tons can be seen as in Fig. 3 showing that 
the penetration is the same here but the 
whole plate demonstrating that the result 
is somewhat less clear, as might be ex- 
pected, in the air than under *a vacuum. 
The difference in the penetration at D and 
at E and F is accounted for by the fact 
that E and F were almost directly over the 
poles of the magnet while D was at one 
side and the penetration was much greater 
at E and F — again proof of the currents 
and of the effect of the magnet. 

I have also produced Magneto-graphs, as 
I have chosen to call them, over an electro- 
magnet and over a straight wire bearing a 
current, but I have not as yet secured 
clear results, owing to the difficulty of 
maintaining a steady current for sufficient 
length of time. 



SOURCES OF ELECTRICITY. 

{Continued from page 12) 

As might be suspected, the voltage pro- 
duced by heating a single metallic couple, 
such as the above, is very small, and where 
a greater potential is desired a large num- 
ber of similar couples are mounted in as 
compact a manner as possible, and all of 
the junctions are heated simultaneously 
by gas or coal as shown in Fig. 6. The 
difference of potential for a bismuth-anti- 
mony couple is about 117 microvolts for 
each degree Centigrade, when the junction 
is heated above the rest of the circuit. The 
total current produced by the massive com- 
pound circular thermopile shown in Fig. 
6 is 80 volts and 3 ampres, which is suf- 
ficient to light a number of incandescent 
lamps. 

Dynamic Electricity : The most success- 
ful and practical source of electrical energy 
as we know it today is the Dynamo. One of 
these machines, which depends upon the 
cutting of magnetic lines of force by a ro- 
tating wire or inductor as it is called, is 
shown in Fig. 7. It was Faraday, who early 
in the 19th century discovered that if a 
circular copper disc be rotated between 
the poles of a strong steel magnet or an 
electro-magnet, that there would be a cur- 
rent produced, or rather induced in the 
moving copper disc, due to the cutting of 
magnetic lines of force. The current was 
found to flow from the shaft supporting the 
disc to the rim, or vice versa, according to 
the direction of rotation. This current was 
conducted away by wires, having sliding 



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brush contacts, one of which was made to 
bear against the shaft, while the other made 
contact with the edge of the disc. 

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the dynamo we have the conversion of 
mechanical energy into electrical energy. 

Electricity from Coal: One of the 
most successful forms of apparatus for 
producing electricity direct from coal is 
shown in Fig. 8. This particular type of 
coal-electric cell is due to W. W. Jacques. 
Here we have a carbon cylinder immersed 
in a fused caustic soda bath ; this is placed 
in an iron vessel which also serves as the 
other electrode of the cell. An air pump is 
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72 



THE ELECTRICAL EXPERIMENTER 



May, 1917 




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idize to C0 2 , which mostly bubbles up thru 
the caustic soda solution and escapes. This 
cell gives about 1 volt E.M.F. The action 
occurring in the production of electrical 
energy is believed to be partly voltaic and 
thermo-electric. The cell has an efficiency 
of about 8 per cent — compared to 12 to 15 
per cent for modern steam boiler and en- 
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to replenish it is said to be at least 34 times 
that for a good steam engine, while the 
residue or ash from such a battery would 
possibly weigh 12 times that from a corre- 
sponding steam plant. 

Plant Electricity : It is not generally 
known that certain plants exhibit pro- 
nounced electrical activity, but such is the 
case. Perhaps the strongest, that is in the 
sense of electrical vibrations, is the sensi- 
tive plant (Mimosa pudica), shown in the 
illustration (Fig. 9). Others, such as iris, 
nicotiana, nasturtiums and practically all 
the meat-eating plants, such as the "Venus 
fly-trap" and the "sundew," afford splen- 
did examples for experimentation. If any 
of these be placed "in connection with a 
galvanometer by means of electrodes at- 
tacht to leaves on different sides, and one 
side of the plant be exposed to sunlight 
while the other side is kept shaded, then 
within froui three to ten seconds after ex- 
posure to sunlight there will be a flow of 
electricity from the lighted to the shaded 
parts amounting to .005 to .02 volt. This 
continues for about five minutes, when the 
magnet begins to swing back and shows an 
opposite current of considerable magnitude. 
The manifestations are similar to those of 
"teranized nerve." 

A better understanding of the electrical 
qualities of plants will, no doubt, explain 
many of the hitherto mysterious habits of 
meat-eating plants. Especially will this be 
true of such terrible and uncanny plant 
monsters as the "devil's snare" of South 
America and the mammoth Utricularia, or 
fishing plant, which lures minnows and 
small animals into its voracious mouth, and 
suddenly, as if an electric button were se- 
cretly prest, closes in upon its helpless 
prey. In other words, it fishes with a net 
electrically wired ! Strange as it may soun A 
this plant safeguarded itself by means of 
its electrical currents ages before we used 
the electric burglar alarm and door bell. 
Were it not for this protection, the plant 
could not live and hold its own in such an 
aurial-infested region as it needs for its 
fishing ground. 

Animal Electricity : Altho not so com- 
monly known, there are in the world several 
varieties of electric fishes and eels which 
possess quite remarkable power. Several 
species of these creatures inhabiting the 
waters of certain parts of the earth possess 
the power of producing more or less pow- 
erful electric discharges. Physiologically, 
the principal creatures of this class are the 
Torpedo, the Gymnotus and the Silurus. 
One of the most powerful electric fishes is 
the Raia Torpedo or Electric Ray, of which 
there are three species inhabiting the Med- 
iterranean and Atlantic. This particular 
specimen is provided with an electric or- 
gan on the back of its head. The organ 
consists of laminae composed of polygonal 
cells to the number of eight hundred or one 
thousand, or even more, which is supplied 
with four large bundle of nerve fibers. The 
under surface of this fish is negative: while 
the upper surface is positive. With the 
Gymnotus or Surinam eel, the electric or- 
gan extends the whole length of the body 
from tail to head. It has been recorded by 
Humboldt that a lively combat ensued be- 
tween a number of electric eels and a herd 
of wild horses, which were driven by the 
natives unconsciously into the swamps in- 
habited by the Gymnotus. This particular 
specimen of electric fish is said to be able 




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Yon benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



73 



to give a most terrible shock, and proves a 
most formidable antagonist when it has 
grown to its full length of five to six feet. 
In the Silurus shown in our Fig. 10, the 
electric current flows from head to tail. 

It has been shown by several scientists 
that nerve excitations and muscular con- 
tractions of human beings are the seat of 
slight electrical currents. For one thing 
it has been shown that the beating of the 
heart really creates rhythmical electro-mo- 
tive force. 

Photo- Electricity : One of the most in- 
teresting sources of electrical energy and 
also one of the most direct methods of 
production of electro-motive forces is found 
in the photo-electric cell. Simply explained 
this remarkable device comprises nothing 
more than two copper plates, one of which 
is perforated and blackened by oxidizing 
in a gas flame, while the rear or second 
plate is polished, and both of which plates 
are placed in a suitable tank containing a 
salt-water solution. One side of the tank 
which contains the copper plates is fitted 
with a glass window and when sunlight, 
or any other source of light, is allowed to 
strike the cell, there is a difference of elec- 
tric-potential set up between the front and 
rear copper plates. This particular cell as 
developed by Mr. Theodore W. Case, was 
described extensively in an article which 
appeared in the September, 1916, number of 
this journal. It was found possible with 
some of these photo-electric cells to obtain 
a voltage of one-tenth and an amperage of 
two-tenths ; the cell delivering a steady 
current as long as the light shown on it. 
It is of course possible to connect a large 
number of cells in series or parallel to ob- 
tain any voltage or current desired. 

Radium Electricity : It is generally con- 
ceded in scientific circles that the activity 
possest by radium is fundamentally electri- 
cal in nature. Radium gives off three 
kinds of rays known as the alpha, beta and 
gamma rays. It is possible to influence two 
of these rays (alpha and beta rays) by 
means of a magnet or an electro-magnetic 
field, which indicates that they are un- 
doubtedly electrical in their fundamental 
structure. Another experiment, which any 
schoolboy can readily perform with a piece 
of radio-active mineral, is as follows : First, 
an electric charge is produced on a sensi- 
tive gold leaf electroscope, so that the leaves 
diverge; then grasp a piece of the radio- 
active mineral (some may be so fortunate 
as to possess a tube containing a small 
quantity of radium bromid) and bring this 
into proximity with the metal ball or disc 
at the top of a charged electroscope. It 
will be noted that the latter loses its charge 
on the gold leaves almost instantly; the 
electronic activity of the radium bromid or 
other radio-active substance used creating 
a change in the electrical field about the 
'electroscope, apparently making it more 
conductive, so that the bound electric charge 
on the gold leaves can escape. Those in- 
terested in the subject of "Radium" and 
the many electrical and other effects cre- 
ated by the greatest mystery of the scien- 
tific world to-day will do well to read the 
extensive article on this subject, which ap- 
peared in the September, 1916, number of 
The Electrical Experimenter.. 



RADIO ENGINEERS DINE. 

The Washington section of the Institute 
of Radio Engineers gave a dinner, March 
third, at the Commercial Club, Washington, 
D.C., complimentary to Brigadier-general 
George O. Squier, chairman of the Wash- 
ington section. The following named gen- 
tlemen from New York participated: R. A. 
Weagant, chief engineer, and David Sar- 
noff, commercial manager, of the Marconi 
Wireless Telegraph Co., of America; Maj- 
or J. Andrew White and W. J. Hernan, of 
the Wireless Press. 



THE IONIC RADIO SYSTEM AND 
THEORY OF IONIC TUNING. 

(Continued from page 31) 
detector and Weston relay are here con- 
nected in multiple, the connections from 
the local side of the Weston relay being 
the same as above described. 

The preferred type of my detector used 
in this system is shown in Fig. 5, and com- 
prises large nickel-plated binding posts 16 
and 17 mounted about two inches apart, cen- 
ter to center, on any suitable material so 
as to support the electrodes 19 and 20. To 
19 a brass rod one eighth of an inch in 
thickness, is fitted a crystal of silicon 21, 
cut in the form of a truncated cone. Its 
base is glued to the rod, the electrical con- 
nection being made by wrapping the joint 
between the brass rod and the silicon with 
tinfoil. The electrode 20 comprises three 
inches of flexible cord, scraped of its in- 
sulation, then bent double and tightly twist- 
ed, the loose ends being cut off evently. If 
the end of the silicon can be ground smooth 
without destroying its sensitivity a polished 
brass rod may be used. 

This makes a detector costing about 35 
cents to construct. It will have a highly 
finished appearance, exceptional reliability, 
unusual sensitivity and require very little 
adjustment, as the parts are fixed perma- 
nently in place. Those trying this form of 
detector resembling the early "E. I. Co." 
Auto-coherer I am sure will be well satis- 
fied. After eleven years of experimenting 
with all forms of commercial detectors 1 
have found this one the only type constant 
enough for quantitative measurements. 

Having described one set of apparatus 
adapted to be operated according to my new 
method of tuning I will now briefly describe 
the characteristics of crystal detectors and 
the theory of operation of both thermo- 
electric and ionic detectors, in order more 
clearly to disclose the exact nature of my 
new method. 

A Thermo Detector consists of a very 
fine point or "cat-whisker" resting upon a 
thermo crystal with a comparatively light 
contact. When an alternating current 
passes to and from the crystal, heat is gen- 
erated in minute quantities at this point. 
This heat causes a "thermo-pile action" and 
generates a thermo-electro-motive force. 
Impulses of alternating current coming in- 
to the detector in such direction that their 
direction is the same as that of the thermo 
e.m.f. are allowed to continue and pass on 
thru the circuit. Those passing in the op- 
posite direction are opposed by the thermo 
e.m.f. and are supprest or wiped out. The 
impulses which reach our 'phones then are 
always in the same direction as the thermo 
e.m.f. Thus is accomplished the rectifica- 
tion by thermo crystal detectors. These 
crystals always require a metallic point and 
to this class of thermo crystals belong the 
following: copper pyrites, tellurium, man- 
ganese dioxid, chalco-pyrites, galena, iron 
pyrites, etc. 

Ionic detectors are also rectifiers but per- 
form their function in a different manner, 
these metal points not being necessary and 
the form of contact being of relatively small 
importance. These detectors have no use- 
ful thermo e.m.f. A large polished plate of 
the crystal may be placed between two high- 
ly polished electrodes and it will work equal- 
ly well, if not better, than with a point. I 
have taken a piece of molybdenite one-half 
inch in length and tacked it to a board with 
a tack at each end. It worked very well as 
a detector and required no adjustment. It 
was not especially sensitive but its operation 
was_ perfectly constant. On the contrary 
an ionic detector rectifies by the polariza- 
tion of its contained ions, an ion being a 
combination of a number of positively 
charged molecules, with one negatively 
charged electron. 




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74 



THE ELECTRICAL EXPERIMENTER 



May, 1917 




THE WORLD IS OPEN 

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Let the pyramids in Fig. 4 represent the 
ions in an ionic crystal, the bases represent- 
ing the molecules and the vertices or points 
the electrons. The electrons or points being 
negatively charged, seek what is to be the 
positive pole of the detector for the recti- 
fied current. The molecules being positive- 
ly charged seek what is going to be the 
negative pole of the detector. When an al- 
ternating current enters the crystal these 
ions are polarized, somewhat as the mole- 
cules of iron in an iron bar are polarized 
in magnetic hysteresis. This makes the 
crystals better conductors in one direction 
than in the other, or in other words they 
become rectifiers. The impulses passing 
thru the crystal in the direction of the 
points (Fig. 4) meet a very low resistance 
and are allowed to continue. The impulses 
coming in the opposite direction, or against 
the points, meet a very high resistance and 
are converted into heat, being to all practi- 
cal purposes thus supprest or wiped out. 
To this class of ionic crystals belong the 
crystals of silicon, molybdenite, perikon 
(copper pyrites and zincite), carborundum 
and titanium dioxid, titanium (TiO..) oc- 
curring in two forms, viz., as the minerals 
brookite and anataste. 

Thus while both the thermo and ionic 
detectors convert alternating current into 
direct current, the former work by a ther- 
mo e.m.f. in one direction, while the po- 
larized ions of the latter cause these crys- 
tals to conduct better in one direction than 
in the other. 

My unique method of ionic tuning de- 
pends upon the following discovery, which 
I have made, viz.: The ions of each chemi- 
cal element or compound have a definite 
rate of vibration, the ionic groups of no two 
elements or compounds having the same 
rate of vibration. Thus each chemical ele- 
ment or compound is sharply distinguished 
from every other element or compound by 
its characteristic ionic vibrati-n rate. 

My novel method of ionic tuning is based 
on this newly discovered principle and I 
make use of the principle in the following 
simple manner — namely, by employing the 
same chemical element or compound in re- 
ceiving the radio impulses as in generating 
them. For example, silicon may be em- 
ployed both in the spark gap at the send- 
ing station and in the detector at the re- 
ceiving station; or, when employing a zinc- 
ite detector at the receiving station, a zinc 
spark gap may be used at the sending sta- 
tion, and I have found that not only can 
excellent selectivity be obtained in this man- 
ner, but the detector is far more sensitive 
to a sender employing the same material, 
thus permitting transmission over much 
greater distances. 

This phenomenon I believe to be due to 
the fact that the vibration of the ions in 
the detector is vastly more easily affected 
by disturbances of the same basic character 
produced in the ether by a sender of the 
same material. On the contrary, when dis- 
similar elements are used in the sender and 
receiver respectively, as has heretofore been 
done universally, the ionic vibration at each 
end is not in unison but is in dissonance. 

In further experimentation along this line 
I intend more fully to study the effects of 
combining two or more elements in both 
the sender and transmitter in order to de- 
termine whether or not any material loss of 
efficiency or other disadvantage results from 
such combination, and I suggest this as one 
of the many fruitful fields of research 
opened for future endeavor by my discov- 
eries herein publicly disclosed for the first 
time. 



It is stated that one result of the war in 
Germany has been the greatly extended use 
of aluminum for many purposes. Its use 
is one of the outstanding features of cap- 
tured German motor construction, being 



used for crank cases, gear boxes and even 
cylinder heads, jackets and shafts. The 
Germans are said to be able to produce 
aluminum very cheaply, largely owing to 
the mining of coal in occupied French ter- 
ritory by forced labor. The cheap produc- 
tion of electricity has also stimulated the 
development of electric motor vehicles, 
which are now being run with nickel-iron 
batteries, owing to the shortage of lead. 

AN ELECTRIC PARADOX OR SE- 
LECTIVE LAMP CONTROLLER. 

(Continued from page 37) 
mechanism. Adjust N so that the travel of 
the armature shaft is such that every time 
it travels from the down to the up position, 
a tooth of the ratchet will have moved the 
distance between two teeth (1/12 revolu- 
tion). 

The three lights to be operated and also 
the knife switch may be mounted on a suit- 
able lamp board as shown in the photo- 
graph. The mechanism just described and 
also the rheostat may be hidden, and only 
the wires coming to the lamp board ex- 
posed. 

I-t will no doubt afford the reader con- 
siderable amusement when he shows the 
device to some of his friends who think 
they are wiring sharks and that nothing 
electrical can fool them. 



A STUDY OF THE LAW OF RE- 
SPONSE OF THE SILICON 
DETECTOR. 

(Continued from page 34) 
ponents of the transmitted waves, loops 
were made with the lengths of the vertical 
and horizontal portions of the wire in vary- 
ing ratios. Curves showing extreme varia- 
tions were obtained. The conclusion to be 
drawn from these curves is that the hori- 
zontal portions of the loop give a maxi- 
mum response at deg. and 180 deg., the 
vertical portions at 45 deg. and 135 deg. 
The receiver responds both to the horizontal 
and vertical components of the waves re- 
ceived, and the position of the maxima 
will vary with the particular form. 

Receiver in Horizontal Plane. 

Since for the study of the law of the 
detector it was desirable to eliminate as 
far as possible all response to the vertical 
component, the entire receiver was placed 
in the horizontal plane and suspended as 
before by rubber bands. To reduce still 
further the response without the resonator 
the short loop which had given the mini- 
mum effect was used. The screen was ro- 
tated thru 360 deg. and readings were taken 
every 20 deg. with and without the reso- 
nator as before. The curves obtained 
showed the effect without the resonator to 
be a much smaller fraction of the entire 
response than under the best conditions 
with the receiver vertical. As a further 
precaution, oscillator, receiver and rotat- 
ing screen were carefully centered. Curves 
obtained under these conditions both with 
and without the resonator had their maxi- 
ma at deg. and 180 deg., and their mini- 
ma at 90 deg. and 270 deg., and the effect 
without the resonator was extremely small. 

The effect for the 90 deg. position of the 
rotating screen, the position of no trans- 
mission, was still to be considered. This 
residual effect with the resonator was about 
15 per cent, of the maximum, and indicated 
that with the screens used there were dif- 
fraction effects which, as might be expected, 
were more noticeable with the resonator 
than without. In order to investigate the 
diffraction the receiver was placed in a tin 
box. The response to the waves did not en- 
tirely cease until the tin cover was made 
completely to enclose the receiver ; even a 
small opening in the cover produced a de- 
cided deflection of the galvanometer. That 



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THE ELECTRICAL EXPERIMENTER 



75 



the effect was due to the action of diffrac- 
ted waves on the receiver was further 
shown by the fact that with the rotating 
screen in the position to allow no transmis- 
sion a wire reflector back of the receiver at 
varying distances clearly indicated the pres- 
ence of nodes and loops at distances apart 
which showed the wave-length to be that 
of the original wave. The average distance 
from node to node was found to be slight- 
ly more than 50 cm., making the wave- 
length approximately 100 cm. 

Final observations were made with the 
receiver in the horizontal position at a dis- 
tance of 225 cm. from the fixt screen, and 
with the oscillator at distances from the 
screen ranging from 120 cm. to 230 cm. 

The Law of the Silicon Detector 

Since for the final curves obtained the 
''receiver was so adjusted as to respond only 
• to the horizontal component of the trans- 
mitted wave, it seemed possible to use the 
data to determine the law of response of 
the silicon detector with a variation in the 
intensity of the incident wave. The data 
already obtained showed the response of 
the receiver for each position of the rota- 
ting screen. Since only the component of 
the wave at right angles to the wires of 
the screen could be transmitted, the am- 
plitude of the transmitted wave varied as 
the cosine of the angle between the wires 
and the vertical. As the receiver was ca- 
pable of responding only to horizontal 
waves, the transmitted component suffered 
a second resolution at the receiver, which 
again cut down its amplitude by the cosine 
of the same angle. Hence the amplitude 
of the component of the wave to which ' le 
receiver responded was proportional to the 
square of the cosine of the angle between 
the vertical and the wires of the screen. 
Presumably the amplitude of the oscilla- 
tions set up in the receiver for different 
positions of the screen was proportional to 
the amplitude of this received component, 
and hence to the square of the same angle. 

In determining the law only those data 
were considered in which the values of the 
current obtained without the resonator were 
small. For each set of readings two curves 
were plotted, with the galvanometer de- 
flections as abscissae and in one case the 
second, in the other the fourth powers of 
the cosines of the angles as ordinates. 

From these results it seems safe to con- 
clude that the rectified current is propor- 
tional to the fourth power of the cosine of 
the angle between the vertical and the wires 
of the rotating screen. 

Since the amplitude of the oscillations in 
the receiver is presumably proportional to 
the square of the cosine, this result indi- 
cates that the rectified current thru the 
silicon detector is proportional to the square 



of the oscillating current in the receiver. 
Austin, in his study of the silicon detector, 
reached the conclusion that for alternating 
currents of ordinary frequencies and for 
oscillating currents of a frequency of 140,- 



000 the rectified currents are approximately 
proportional to the square of the alternating 
currents. The results of the investigation 
of the writers confirm this law for a fre- 
quency of approximately 3X10". 



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Order today to avoid delay 

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The word "rebuilt" has been abused and misused until it has become a 
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7 6 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



STRONGER WIRELESS 
COMMUNICATION. 

Another record-breaking achievement in 
the wireless art has been accomplished by 
the Marconi system in establishing strong, 
direct and continuous communications over 
twelve-hour periods between the station of 
the Marconi Wireless Telegraph Company of 



America at Chatham, Mass., and that of the 
English Marconi Company at Carnarvon, 
Wales. The signals received at Chatham 
from Carnarvon were from three to eight 
times as strong as those obtained from any 
other "European station. These tests were 
successfully carried out on January twen- 
ty-ninth and thirtieth. 



A SIMPLE ELECTRIC MOTOR AT- 
TACHMENT FOR PHONOGRAPHS. 

{Continued from page 40) , 

other two holes mentioned are intended to 
take the bolts that run through the motor. 
These bolts are lengthened, by the addi- 
tion to their ends of Yi inch binding posts, 
as shown in Fig. 1, upper end of the motor, 
or are replaced by new bolts long enough 
to extend through the top board, so as to 
support the motor. In the writer's case 
it was a simple matter to find two short 
binding posts which would screw on to 
the ends of the motor bolts. With these 
in place the motor shaft was inserted 
through the center hole, the binding post 
slipping into the other two holes, and the 
thumb bolts which fit the top threads of 
the binding posts, were fitted with soft 
rubber washers, inserted in place and 
screwed up tight to hold the motor in 
place. The rubber washers mentioned 
above deaden the hum of the motor con- 
siderably, but if their effect is not great 
enough two thin washers, made from 
banner felt, can be inserted between the 
motor top and the talking machine top, 
being held in place by the motor bolts and 
bearing as shown in Fig. 1 at b. 

The belt should be crossed in order to 
drive the turntable properly ; the electric 
motor having its field winding terminals 
reversed if it rotates in the wrong direction. 

A simple white string belt, about 1/20 
of an inch in diameter, has been used for 
about two months with excellent results 
by the author, although at first several 
materials were tried experimentally, such 
as leather, rubber, tape and laces. Besides 
being the simplest to obtain and make up 
the string belt gave the best service, and 
is still in use, although the diameter is 
reduced about 30% by wear. The ends 
of the belt were simply joined by being 
tied in an ordinary knot. This belt is 
readily renewed. 

When the driving mechanism has been 
completely assembled one end of a flexible 
lamp cord can be attached direct to the 
motor wires, after first being passed 
through the hole which formerly contained 
the crank handle, for winding the motor. 
The lamp cord may be connected to a lamp 
socket and the motor controlled by the 
key switch in the socket, or if so desired 
a simple push button switch can be con- 
nected to the cord near the machine, or 
else set into the body of the machine itself. 
The regular stop, with which the phono- 
graph was originally fitted, should be kept 
in release by means of a small tack or 
phonograph needle driven into the machine 
top to hold the lever at starting position. 

The records can be readily changed 
without stopping the machine, provided 
the turntable is not held back too much 
by clumsy manipulation of the records. 
This practice, however, is not to be espe- 
cially recommended, and is not at all neces- 
sary, as the machine with an electric motor 
attachment attains full speed very quickly 
upon starting. The speed can of course 
be regulated in the manner already ad- 
vised, by the ordinary speed lever. 



WIRELESS TELEGRAPHY. 

{Continued from page 27) 
Azores, to the western shores of Europe, 
to Madeira, Cape Verde, the mouth of the 
Amazon, Panama, the Galapagos Islands 
off the western coast of Ecuador, and Mag- 
dalena Bay. The radius also embraces 
thru the chain San Francisco and the whole 
stretch of the California, Washington and 
Oregon coasts, the lonely wastes of Upper 
Canada, Hudson's Bay and the southern 
nose of Greenland, the entire Caribbean 
(Continued on page 78) 



OF SLIGHTLY 
DAMAGED BOOKS 



FIRE SALE!! 

A fire in our stock rooms caused many books to 
be damaged by smoke and water. Every one is 
good except for covers and contains just as much 
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we cant sell them for new. Rather than dis- 
pose of them to dealers, we prefer to 
give our readers the benefit. What we 
offer you is a combination of 

Our Celebrated Wireless Course 
(160 p. 400 illus. flexible cloth) 
Reg. Price $1.00. 
List of Radio Stations of the World 
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The Experimental Electricity Course 
(160 p. 350 illus. stiff cloth) Reg. 
Price $1.00. 
How lo Make Wireless Sending 
Instruments (100 p. paper) Reg. 
Price $.25. 

Remember the books are damaged but in many cases only (he bindings have a 
few water spots. But every book is absolutely complete. 

This is the biggest bargain in books we have ever offered. You should take advantage 
of it at once. Send to-day. Remit by cash, postal or express money order to 

THE EXPERIMENTER PUBLISHING CO., Inc., 2 n 3 e Vy u o l rkci^ r n ee y t 




FOR 
PRE 



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IT'S INVALUABLE YET 
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A course that tells you everything you can possibly want to 
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less" are unfolded to you by the use of such simple lan- 
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bowever, for there Is a whole lesson devoted to theTheory 
and Mathematlcsof this epoch marking subject To lend 
charm to the Course, the last Lesson (No. 20) is devoted 
to a history of Wireless and the men who developed it. 
The wireless course positively cannot be bought, but will 
be sent absolutely free with a full year's subscription 
(12 numbers) to the Electrical Experimenter at SI. 50. 
It's the bigeest money's worth you can ever buy any- 
where at any time. Send for It today enclosing $1.50. 
Sena now before you lorget. 

The coupon below Is a convenient way. But do it 
now. 

THE EXPERIMENTER PUB. CO., Inc. 
Publisher 

"The Electrical Experimenter Magazine." 



EXPERIMENTER PUB. CO., 233 Fulton St., New York 

Gentlemen: 

On your absolute guarantee that your 20 Lesson Wireless Course is just as des- 
cribed by you, you may send me same FREE. You are to send me this Course at once, 
all charges paid, and enter my name for a full year's subscription to the Electrical 
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May, 1917 



THE ELECTRICAL EXPERIMENTER 



77 



Read iki$Reiiiaikaltlf Offei ! 




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Price $1.00 if bought alone. FREE with a year's subscription. 



The most comprehensive Wireless Course ever printed. Con- 
tains 160 pages, 350 illustrations. Size of book d]/^" x 9." 
Very fine flexible linen cover. 

Price $1.00 if bought alone. FREE with a year's subscription. 




^Electrical m 
Experimenter 9 




This is a very limited offer. It may be withdrawn at any time, due to the 
tremendous cost of paper, which IS JUST DOUBLE WHAT IT WAS ONE 
YEAR AGO. We only have about 2000 each of these fine books on hand ; after 
they are gone we cannot reprint the books until conditions become normal again. 
THIS MAY BE TWO YEARS OR MORE. Now is your chance. 
The publishers of this journal have earned an enviable reputation of giving 
more than 100 cents' worth for each dollar spent with them. Profit by this liberal 
opportunity NOW; it may never be made again. 

HERE'S THE OFFER 

Subscribe to THE ELECTRICAL EXPERIMENTER for one year, at 
the regular subscription price of $1 .50 per year (Canada and for- 
eign $2.00) and we will send you FREE POSTPAID, either one of 
the above books. If you subscribe for two years, BOTH BOOKS 
WILL BE GIVEN FREE, POSTPAID. 



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12 copies of THE ELECTRICAL EXPERI- 
MENTER make a book 9" x 12" and 4" thick. 
This book will weigh 7 lbs. 1 1 is the greatest 
Electrical and Wireless reference <fc"| CA 
work in the world. And all for «pl»W 



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wonderful opportunity anyway. If you do, we will extend 
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78 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



Sea, all of the West Indies, most of Peru, 
all of Colombia, Venezuela, the three Gui- 
anas and the watershed of the Amazon; 
and all of the United States, Mexico and 
the Central American Republics are with- 
in the range of these stations. Weather 
reports and time signals and also informa- 
tion in regard to ice, obstructions to navi- 
gation, etc., are sent out broadcast for the 
information of navigators. 
The success of Marconi in effecting trans- 



oceanic communication was a startling 
achievement. Regular message traffic has 
been transmitted between Europe and 
America continually for more than eight 
years over a duplex wireless circuit be- 
tween Clifden and Glace Bay; that is to 
say, messages between these points are 
transmitted in either direction simultane- 
ously. The transmitting and receiving ap- 
paratus of a station are not placed close 
together, but several miles apart. 




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what the "How-to-make-it Fiend" really 
wants. In these two hand books are 
concentrated the most important, up-to- 
date wireless instruments and directions 
how to make them. They are by far the 
most successful wireless books of the 
season. Size of each book is 5x7 inches, 
substantially bound on a good book 
paper. The covers are in two colors. 
We really can not praise these works 
too highly. You will be delighted with 
them. 



EXPERIMENTER PUB. CO., 233 Fulton St., New York 

Gentlemen: 

On your absolute guarantee that your two big Wireless Handbooks are just as 
described" by you, you may send me same FREE. All charges prepaid. You are to 
send me these books at once, and enter my name for a full year's subscription to the 
Electrical Experimenter, 12 numbers, for which I enclose *$1.50, the price of the Electrical 
Experimenter alone. 

(If a 2-year subscription is desired, enclose $2.85.) 

My name is ■ 

M y address is. 
(5-17) 



*Canada and Foreign Countries, $2.00—2 years, $3.85. 



EXPERIMENTAL CHKMTSTRY. 

{Continued from page 52) 

base, the metal of the base enters into the 
acid in place of the hydrogen and the hy- 
drogen combines with the hydrogen and 
oxygen of the base to form water. 

HNO3 + KOH = KNO3 + K2O 

Nitric Acid Potassium Potassium Water 
Hydroxid Nitrat 

H2SO4 + 2NaOH = Na 2 S0 4 + 2H2O 
Sulphuric Sodium Sodium Water 
Acid Hydroxid Sulpha t 

NOMENCLATURE OF SALTS— 

The name of the salts containing oxy- 
gen are derived from the name of the 
corresponding acid. The characteristic 
suffix of the acid is changed to indicate 
this relation. Thus, the suffix ic becomes 
ate, and the suffix -ous, becomes -ite. 

_ [Note: The final "e" is usually dropt in 
simplified spelling as used in this journal.] 

Sulfuric acid form Sulfate 
SulfuroMj acid form SulHtes 
Nitric acid form Nitrate 
Nitrous acid form Nitrite 
Chloric acid form Chlorate 
Hypochloremic acid form Hypochlorite 
Permanganic acid form Permanganate 

The name of the replacing metal is re- 
tained, as, Potassium chlorat, sodium sul- 
phat, calcium hypochlorit, potassium per- 
manganat. Notice that the prefixes Hypo- 
and Per- are not changed. 

The names of salts containing only two 
elements, following the general rule for 
binary compounds, end in ide. This suffix 
is added to a modification of the name of 
the non-metal, giving the names chlorid,. 
bromid, sulphid, fluorid, etc. The prefix 
Hydro- which is contained in the name of 
the acid is omitted. Thus, the name of 
the sodium salt of hydrochloric acid is 
sodium chlorid; similarly, there are the 
names potassium chlorid, calcium fluorid, 
and sodium iodid. Sometimes, the salts of 
these hydrogen acids are called Halids, to 
emphasize their relation to common salt, 
which in Greek is called Hals. 



A CLEAR 
TRACK TO 




FOR THE 
TRAFFIC 
v~ rj5> INSPECTOR 

Learn this new profession in 3 to 4 months 
with our complete course. Prepare for big 
pay — promotion — success. Railroads every- 
where are watching for good traffic inspectors. 
The tiaining obtained in this work leads to- 
sure opportunities for advancement. 
Get ready for the success that awaits you. Earn 
big pay with short hours. Travel at no expense. Our 
Employment Bureau helps successful graduates obtain 
positions. Write now for booklet G-12, giving full in- 
formation. 

FRONTIER PREP. SCHOOL - Buffalo, N. Y. 




SPARK COILS For v irckss 

STYLE C SPECIAL f C0I14? CA 
Postage extra 1 «J)e)»<PU 

FINE RESULTS WITH THIS COIL 
SCHUG ELECTRIC MFG. CO. 

254 EAST LARNED, DETROIT, MICH. 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



May, 1917 



THE ELECTRICAL EXPERIMENTER 



79 




Scientific Exchange Columns 



UNDOUBTEDLY you have at the present time some things for which you have no further use. Do you wish to exchange them 
for something, for which you have immediate use? There is no surer and quicker way to do this than by advertising your 
articles in these columns. The Very people, the Only people, who could possibly have a use for your things read this journal. 
More than 75.UOO interested people will see your acf. It is furthermore the cheapest advertising medium for you in the country. 
Dealers' advertising accepted in Opportunity Exchange Columns only. 

The rates are: Three cents per word (name and address to be counted), minimum space 3 lines. Count about 7 words to the line. 
Remittance must accompany all orders. No advertisement for less than 50c. accepted. 

We reserve to ourselves the right to refuse any advertisement which we consider misleading or objectionable, j Advertisements for 
the June issue should reach us not later than April 25. 

1 he Classified Columns of "The Electrical Experimenter" Bring Positive Results. 
Subscribers experiencing trouble in dealing with any advertiser should notify the publisher very promptly. 

OVER 75,000 PEOPLE READ THIS JOURNAL 



3 



FOR SALE — As am not permitted to erect 
aerial will sell my new cabinet receiving set. 
Contains large loose coupler, primary and secon- 
dary loads, variable and fixt variable condensers, 
detector, potentiometer, buzzer test anchor gap. 
All instruments enclosed, with switch and lever 
control. With Brandes headset $50. Send 5c. 
stamp for photo.' Also spiral helix $2. Spark 
Coil $1.50, tuner 14 inches long $1. Switches, 
detector parts, several lbs. fine wire and wireless 
books. Wanted, for cash, catboat or rifle. Len K. 
Wright, 518 East 83d St., N.Y. City. 

FOR SALE— M K.W. Closed-core Transformer, 
$8.50. Also 200 W. Step-Down Transformer with 
6, 12, 18, 24 V. taps, $3. Both in first-class con- 
dition. F. K. Billau, 525 N. Delaware, Indian- 
apolis, Tnd. __ 

FOR SALE — International Correspondence 
Schools' course in arithmetic. Also wireless ap- 
paratus, cheap. Alex. Serna, Lehigh, Okla. 

ATTENTION— Sale or Exchange: Motor, $20; 
lathe, $35; generator, $6; motor, $6. Stamp for 
descriptions. H. E. Neefe, La Farge, Wis. 

EXCHANGE — Five volume set of Automobile 
Cyclopaedia, red cloth bound, gold stamped, also 
six volume set of Modern Shop Practice, flexible 
leather binding (published by American Technical 
Society), current editions, for receiving or sending 
apparatus of standard make. Charles B. Hayward, 
Great Neck Sta., New York. 

IF ANY ONE can give me the address of W. B. 
Dougherty it will be thankfully received. Chas. 
Dougherty, Louisiana, Mo. 

WANTED — Coil rated at 2 inches. Will pay 
cash. Henry Kienzle, 501 East 84th St., New 
York. 

FOR SALE OR EXCHANGE— 1 5,000 M. Loose 
Coupler, $10, also small Loose Coupler, $4, or will 
exchange for Variometer or Audion. Wanted to 
buy good polarized relay. Write to J. Cingature, 
866 Thirteenth nve., Milwaukee, Wis. 

FOR SALE — $5, 22 revolver shot six times, $3; 
loading coil, $1; automatic telephone, $3; $6.50 
moving picture machine, $4. William D. Peteet, 
Greenwood, Miss. 

EXCHANGE— Good mandolin with case, for 
typewriter. Write if interested. Wm. Bolme, En- 
loe. N.Pak. _____ 

SALE — Telegraph Instruments, Motors, etc. 
See ad in April Experimenter. Sydney Young, 
Jr., Addison, N.Y.. R.F.D. No. 4. 

FOR SALE— Three-inch coil, $9; relay, $3; 
medical coil outfit with meter, cost $100, sell for 
$16. Ford electric starter and generator, $20 
Gorham Cottrell. 1628 Jersey, Ouincy, 111. 

FOR SALE OR EXCHANGE— Railroad motor 
car for electrical goods. S. R. Kimball, Diamond 
Bluff, Wis. 

BARGAIN — Rotary gap having Klitzen disc and 
110-volt Universal motor, $6. Fred Ancona, 16th 
St., & Mineral Spring Road, Reading. Pa. 

FOR SALE— 1,500 meter tuning coil; 1,000 
meter tuning coil; detector, 60c. All new, make 
offer. Francis H. Coleman, 27 Salem St., Spring- 
field, Mass. 

4-Step Packard Transformer in paraffine wax 
and oak case, E. I. Government phones, 5 lbs. 
No. 22 D.S.C. wire. Cheap. Best offer takes them. 
F. Allen, Bliss, Takoma, D.C. 

FOR SALE — Two brand new DeForest ampli- 
fiers with burned out bulbs. Price right. Palmer 
Southworth, 34 Montowese Street, Hartford . Conn. 

FOR SALE — 200 watt transformer. Steps 110 
to 10, 20, 30 or 40 volts, $10; 40 watt dynamo or 
1/12 H.P. motor, $7; Inch spark coil; fine fat 
spark, $4; Testing magneto, $2.50; 20 ohm sensi- 
tive pony relay, $1.50; 20 ohm giant sounder and 
steel key, $2.50; Portable voltmeter, 1-20 range, 
$1.50; Filings coherer, $1; 75 ohm wireless re- 
ceiver with headband, $1.25; 1/12 HP water 
motor. $1.50. C. M. Adams, Milford, Ohio. 

SELL — 40 1 esson Taxidermy Course, $9. Trade 
3 yrs. Youth's Companions for Al, 2 slide tuner. 
William Litwiller. Hopedale, 111. 



FOR SALE— 110 volt, l'/S ampere dynamo ($12) 
used very little. J. T. Greene, Carrs, Ga. 

FOR SALE— Hytone Clapp-Eastham V2 kilowatt 
transformer in original case. No helix, gap, or 
condenser. Bargain, $15. Perfect condition. Also 
new rotary gap. Never used. Adams Morgan 
make, Robbins & Myers 110 V direct current 
motor speed 3,000. This gap will be just the thing 
for the Hytone transformer, $8. Both for $21. 
All letters answered. Ralph B. Austrian, 49 St. 
Nicholas Terrace, New York City. 

EXCHANGE — "Remy" magneto with vibrator 
and 1 inch coil without vibrator for 3,000 ohm 
Phones or what have you? Walter Heinrich, 15 
Colby St., Lawrence, Mass. 

FOR SALE — Extremely sensitive Audio-Tron 
bulb, $4. Send for list of wireless goods. What 
have you for sale? Henry Lehmberg. 5116 N. 
12th St., Philadelphia. 

WANTED — Burnt out De Forest Audion Bulbs. 
Will pay cash or exchange wireless goods. Joe 
Singer, Goldfield . Nevada. 

FOR SALE — Tigerman Detecto-Amplifier Type 
C, panel type with two bulbs, $16. Eddie Smith, 
688 South 39th St.. Louisville. Ky. ■ 

FOR SALE — Thor motorcycle, good running 
order, has up-to-date equipment. Bargain at $35. 
Also Thor motorcycle complete except for engine 
at $10. Harvey Adams, Chambershurg, 111. 

WANTED— R.J. 9 Audion and storage battery, 
43 plate variable and E.I. or Murdock loader. 
L. H. Hammond, Box 51, Baden, N.C. 

plllllllllllllllllllllllUlilllllllllllllllllllip 

I TALK ABOUT RESULTS! I 

m 17 PRYER LANE, g 

= Larchmont Manor, N.Y. = 

g The Experimenter Pub. Co., 

= New York City m 

{§ Dear Sir:— : 

g Talk about results! You've got to {§{ 

§§ give it to the "E. E."to reach the B 

{§ right people. On the day after " E. |j 

§j E." came out I received'a reply and S 

H they have been coming in at the rate I 

jj| ofoneaday. If Ieverhaveanything H 

! else that I want to sell I will send pj 

H my " ad " to vou every time. 

H Yours truly, = 

B Clarence de Witt Rogers, Jr. B 

IlillllllllllllllllllllllllllllllllllllllllillllllllllllllllWIIII 



NEW $18. Multi-Audi-Fone, $12. Mesco, $12. 
Intensifying Coil, $7.50. $15 Army binoculars 
in leather case, $9. All perfect. Peter Pinkston, 
Valdosta, Ga. 

FOR SALE— Pocket Wireless Set 3,000 meters, 
$2.75; Redhead single head set, $1.85. Max Vin- 
eski, Troy, Pa. 

EXCHANGE for $16— One Smith Premier No. 4 
typewriter, excellent condition, used only short 
time. Fred Fries, 60 E. Bringhurst St., German- 
town, Philadelphia, Pa. 

FOR SALE OR EXCHANGE — 1 54 H.P. Gaso- 
line Engine nearly new, $20. Wanted, */ 2 H.P. 
Gasoline engine. Must be in good condition. 
Glenn Johnson, Missouri Valley, Iowa. 

TO EXCHANGE — Chemical laboratory, value 
$15 for wireless instruments. J. Y. Parsons, 1906 
Park St., Kansas City, Mo. 

FOR SALE— Cash only, almost new, half K.W. 
Blitzen transformer mounted in mahogany, worth 
$24 at $15. Also R.J. 9 Audion new bulb, $12. 
New Audio-Tron Panel, two filament. $9.50. Also 
one K.W. transformer, new, at a bargain. All 
these instruments good as new. Holtzer-Cabot 
phones, new, $7. Don D. Tullis. 59 N. Second 
St.. Newark-, Ohio. 

FOR SALE— 10 vols. Hawkins' Electrical Guides 
and one vol. Rogers' Mechanical Drawing. Cost 
$12, sell for $7.50. M. Jacobson, Parksville, N.Y. 



FOR SALE OR EXCHANGE— Crookes Spin 
thariscope, $8; Thomson A.C. voltmeter, 0-175. 
$4, A.C. Ammeter, 0-100, $4. Tuning cabinet hard 
rubber panel, variometer coupling, no variables, 
neat, compact and efficient, $12. Home-made 
transformer coil, about 300 watts, $4. Wanted, 
small lathe, oscilaudion, variables, books or tools. 
Experimenter, 2808 N. Lawrence St., Philadel- 
phia, Pa. 

WANT TO EXCHANGE lenses, camera and 
electrical measuring instrument, etc., for old coin 
and stamps. James Christie, 107 Vanderbilt Ave., 
Brooklyn. N.Y. 

FOR SALE — Tubular Sending Condenser; po- 
tentiometer; water motor; large tuning coil; box 
of wire; screws, etc.; one ten plate sliding con- 
denser, etc. All for $5, as I have no more use 
for same. Write or call evenings, Henry A. Gil- 
man, 156 Jerome St., Brooklyn, N.Y. 

FOR SALE OR EXCHANGE— Brandes Navy 
Phones, $9.25; regenerative coupler, $6; Clapp- 
Eastham .002mf variable, $5.75; Murdock 43 
plate variable, $3.10; Murdock wave meter, $5; 
Bunnell key, 75c; Standard gap, $1; Murdock ro- 
tary gap in sound proof mahogany case — cost $20 
and is brand new, $11.50; 5 K.W. Aerial switch, 
$5; Amplifying coil, $5; 5 K.W. Oscillation trans- 
former, $10; 2 sections Murdock Moulded Con- 
denser, $3; 600 feet No. 12 copper aerial wire. 
$4.75; 8 Ball Insulators, $1; two 10^2 inch insu- 
lators, 75c; Lightning switch, $1.25; two 15 foot 
poles, $5; two spreaders, $2; Winchester model 
1906 repeating .22, $8; Surgeon's dissecting in- 
struments, $7.50; L. C. Smith typewriter, cost 
$97.50, $45. H. W. Semmelmeyer, 2629 N. Fair- 
field Ave., Chicago. 111. 

SACRIFICE — Smith motor wheel, $35. Particu- 
lars on request. Best condition. Francis Pray, 
1 02 Heath St., Winter Hill, Mass. 

WILL EXCHANGE a Keystone milli-ampere 
meter excellent for radio measurements, a Gov- 
ernment type Perikon detector, finely finished. 
Want small 110 volt A.C. motor, rotary variable 
condenser, A.C. voltmeter or ammeter, or what 
have you? Samuel Cohen, 1936 Pitkin Ave., 
Brooklyn , NVY. 

POWERFUL Waite-Bartlett Static Machine. 
8 rotary, 8 stationary plates. Gives heavy 16-inch 
condenser charge. Excellent for X-rays and ex- 
periment; perfect condition and best workmanship: 
complete. Cost over $300. $75 or best offer in 
wireless. Photos and details upon request. T. 
Earl, Niles, Mich. 

FOR SALE — Mandolin, good as new, cost $15. 
Will sell for $10 cash. Instruction books, music 
rack, case included. Joseph Dushek, Post Office 
Box No. 114. Owatonna. Minn. 

INDIAN TWIN just overhauled, $70; or trade 
for marine engine, 6-15 H.P. H. Griffin, Hart- 
selle, Ala. 

HAVE— Oliver Typewriter, Model 3. Want 
cash or receiving apparatus. Make offer. All let- 
ters answered. Herbert Richter, Collegeville, 
Minn. 

BARGAIN — Complete new Blitzen Receiving 
set with extra equipment. Holtzer-Cabot Phone?. 
In perfect condition. Write for particulars. Chas. 
Bayliss, 68 Peterboro St.. D etroit. Mich. 

FOR SALE — Complete Audio-Tron on panel 
with all controls and 4-40 storage battery. Panel 
has 2 D.P.D.T. mineral change-over switches 
wired on. Used 10 hours. $10. Also "Arlington" 
4,000 M. Coupler, cost $9, for $6.60 and $4. 
Murdock Oscillation for $3. George R. Ham- 
mond. Oelwein, Iowa. 

WILL EXCHANGE my Twin-Cylinder, 6 H.P. 
Merkle motorcycle, in perfect condition, for good 
wireless apparatus. Francis Joannini, 3326 17th 
St., Washington. D.C. 

FOR SALE— Set Cyclopedia of Applied Elec- 
tricity. Send for description. All letters an- 
swered. J. N. Boyington, South Galena Ave., 
Freeport, 111. 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



8o 



THE ELECTRICAL EXPERIMENTER 



May, 1917 



FOR SALE — Steam engine designed for com- 
mercial use. Bore seven-eighths, stroke 2 inches; 
and Hoyt voltameter, both cheap; $6 cash. A bar- 
gain. John N. Lint, Box 171, Meyersdale, Pa. 

FOR SALE— Almost new Vz K.W. Blitzen un- 
mounted transformer, record of this transformer 
is 300 miles. 10 volumes "Hawkins Electrical 
Guides" good as new. Write, Hansford Penning- 
ton, 1505 Wyoming St., San Antonio, Texas. 

QUICK— Type S S Motor, $4; 2 slide tuner, 
loading coil, condenser, 2 detectors, $6. All new, 
perfect condition. Send stamp or list. All an- 
swered. Chester Shurr, Berthold, N.D. 

FOR SALE OR EXCHANGE— One 15,000 
meter coupler, one receiving set, one 4'/2 H.P. 
gasoline engine. Wanted Omnigraph or what have 
you? F. B. Dadisman, Independence, W.Va. 



FOR SALE— One Electro Selenium Cell, $3.50. 
Two-inch Bulldog Spark coil, $4.50. Gernsback 
Interrupter, $1.75. Electro vario-selective coupler, 
$4.50. Electro Amateur phones 2,000 ohms, $3. 
Electro rotary variable condenser, $1.75. Electro 
fixt variable condenser, 75c. Crystaloi Detector, 
$2.25. ■ Two Electro high voltage condensers, $1. 
Knapp Type S S Dynamo Motor, $3. Stromberg 
Transmitters, new, 75c. Telephone Induction 
Coils, 50c. New receiver cords, 3 ft., 15c, 6 ft., 
25c. All these articles are new and guaranteed. 
Prepaid. Will trade for Smith Premier Type- 
writer No. 2. F. A. Steinbrook, Brookville, Pa. 



TRADE — }4 h.p. 133 or. 125 cycle A.C. Motor 
for Audion, Audiotron, or Transmitting Appara- 
tus. H. C. Ross, 1087 Schiller St., Columbus, 
Ohio. 



BARGAINS— Crocker-Wheeler 8 V. 1600 
R.P.M. motor, $2. Rebuilt 6 V. Storage Battery, 
$6. Inch Spark Coil, $2.50. Many other bar- 
gains. Write for specifications. H. R. Huth, 
Beaver Dam, Wis. 

WANTED — Two kerosene or gasoline engines, 
one horse-power, second-hand, good order. 
Bra nchaud Bros.. Rutland, Vt. 

V2 H.P. GASOLINE ENGINE, 2000 ohm Red 
Head Phones (new), 500 ft. Aerial Wire, Coils 
of Variometers, Loose Couplers, etc., Detectors, 
Condensers, 4 lbs. Wire, Binding Posts, Switch- 
es, Knobs, Buzzers, Miniature Lights, Sockets, 
Pump Gun, etc. First money order for $15 takes 
all. E. Myers, 499 So. 21st St., Irvington, N.J. 

EXCHANGE— New Telephone goods, large Mec- 
cano, gun. Want wireless goods, banjo or re- 
volver. Towns, Marlboro St., Keene, N.H. 




Opportunity Exchange 



VOU will probably find more opportunities and real bargains in these columns than anywhere else in the country. Most good things in 
A life are hard to find and worth going after — these little ads illustrate that point; you alone will be the real loser if you don't take the 
time to scan through these columns. 

Advertisements in this section 4c. a word for each insertion. Count 7 words per line. 

Name and address must be included at the above rate. Cash should accompany all classified advertisements unless placed by an ac- 
credited advertising agency. 

Ten per cent, discount for 6 issues, 20 per cent, discount for 12 issues from above rate. Objectionable or misleading advertisements not 

accepted. 

Advertisements for the June issue should reach us not later than April 25. 

OVER 75,000 PEOPLE READ THIS JOURNAL 

EXPERIMENTER PUBLISHING CO., INC., 233 Fulton Street. New York, N.Y. 



j 



BOOKS 

TO GET BETTER PICTURES: Read the 
Amateur Photographer's Weekly; illustrated; 
weekly prize competitions; print criticisms; many 
unique features; $1.50 per year; three months' 
trial subscription 25c; Abel Publishing Company, 
401 Caxton Bldg., Cleveland. Ohio. 

HUNTING AND FISHING GUIDE— Most 
complete work on the subject printed. Handy 
volume for all sportsmen. Postpaid for only 25c. 
Iona Press, Box 103, Oak Park. 111. 

STUDY SALESMANSHIP AT HOME— Ex- 
pert course. Copyrighted. 15 lessons complete, 
$1. Central Company, 599 Ninth Ave., New York. 

DO YOU WANT back numbers of The Elec- 
trical Experimenter;' Send for bound volume 
No. 3, containing issues from May, 1915, to April, 
1916. Price $1.25. Postage on 7 lbs. is extra. 
Experimenter Pub. Co., 233 Fulton St., New York 
City. 

BOOKS — Scientific and wireless supplied. Let 
us know what you want and we will quote you. 
Experimenter Pub. Co., 233 Fulton St., New 
York City. 

A BINDER for The Electrical Experimenter 
will preserve your copies for all time. Price 50c. 
Postage on 3 lbs. is extra. Send for one to-day. 
Experimenter Pub. Co., 233 Fulton St., New 
York City. ^^^^^^^^^^^^ 

HELP WANTED 

MEN AND WOMEN, 18 or over, WANTED 
for U.S. Government Life Jobs. $75 to $t50 
month. Steady work. Short hours. Rapid (ad- 
vancement. Common education sufficient. Write 
immediately for free list of positions now easily 
obtainable. Franklin Institute, Dep't B 2*7, 
Rochester, N.Y. 

MISCELLANEOUS 

ELECTRICIANS— Send 50c. for 10 Blue 
Prints of Motor and Generator Connections. 28 
for $1, 10 A.C, 4 D.C. Motor Winding Diagrams 
for $1 or 20 A.C, 4 D.C. and 4 Rotary Converter 
Drawings, $1.60. Winding made easy. Martin 
Electric Co., 329 Irvington PI., Denver, Colo. 

COLLECT AND SELL names and addresses in 
your spare time. Big income. No canvassing. 
Detailed instructions, 10c (coin). National Ex- 

change, 1314 Park Ave., New York. 

EVERYBODY WANTS IT— Folding pocket 
Coat and Hat Holder. Can attach anywhere and 
remove instantly, nickel-plated. Sample 10c. Big 
seller for agents. Wedge Mfg. Co., "Km'-' Bing- 

hamton, N.Y. 

STAMPS — 75. all different, free. Postage 2c. 
Mention paper. Quaker Stamp Co.. Toledo. Ohio. 

250 Letterheads, Envelopes or Radiogram 
blanks, $1.50, prepaid. Record, Media, 111. 

DO YOU WANT to buy. sell or exchange? 
Send 5c. for the Busy-Bee Exchange, also list of 
things you have to sell or exchange. Busy-Bee, 

174 Plymouth St.. New Haven, Conn. 

AGENTS — 500% profit putting initials on auto- 
mobiles. Particulars sent free. Address, Auto 
Monogram Co., 2025 E. Monmouth St., Philadel- 
phia. Pa 



etc., 25c Satisfaction guaranteed. Circular 
free. Associated Phonograph Co., Dept. E. Cin- 
cinatti. 



PHONOGRAPHS 

BLTILD YOUR OWN PHONOGRAPH or man- 
ufacture them for profit. Drawings, instructions, 



PATENT ATTORNEYS 

IDEAS WANTED— Manufacturers are writing 
for patents procured through me. Four books with 
list of hundreds of inventions wanted sent free. 
I help you market your invention. Advice Free. 
R. B. Owen, 130 Owen Bldg., Washington, D.C. 



PATENTS— R. Morgan Elliott ,& Co., Patent At- 
torneys, Mechanical, Electrical and Chemical ex- 
perts, 716-724 Woodward Bldg., Washington, D.C. 



PATENTS — Without advance attorney's fees. 
Not due until patent allowed. Send sketch for 
free report. Books free. Frank Fuller, Wash- 
ington, D.C. 



PATENTS ON EASY PAYMENTS. Send 
model or sketch for Free Search and Certified 
Registration of Your Invention for your Protec- 
tion. Free Book tells what to Invent and How to 
Obtain a Patent on Easy Payments. C. C. Hines 
& Co., 593 Loan & Trust Bldg., Washington. D C. 



PHOTOGRAPHY 

AMATEUR PHOTOGRAPHERS— Send for 
our catalog on photo supplies. We retail to you 
at wholesale prices. Films developed, 8c. Cort- 
land Merchandise Co., Dept. E., 1851 N. Kil- 
dare Ave., Chicago, 111. 



MARCONI — We have a limited number of pic- 
tures of Guglielmo Marconi, Nikola Tesla, and 
Dr. Lee DeForest that are done in sepia on fine 
India paper. Fine for decorating your wireless 
room. 10c. each postpaid. Experimenter Pub- 
lishing Co.. 233 Fulton St., New York City. 



WIRELESS 

ELECTRIC MOTORS at unusual low prices. 
1/6 H P., $6; Vt H.P., $5; 1/16 H.P., $4. Other 
prices on application. A. J. Temps, 1690 Grove 
St., Brooklyn, N.Y. 



FOR SALE OR EXCHANGE— Tungsten steel 
magnets', lifts 30 lbs., $1; Telephone magnetos, 
75c; Automobile Transformers, $2.50; 6 volt 
Starter-motor, $15; generators, $15 and $8; Small 
motor-generator, $1; Battery charging outfit for 
Fords, $6.50, automobile magnetos, coils and parts, 
cheap. Want coils, Volt and Ammeters. Albert 
Onody, 336 Oak Street, Buffalo, N.Y. 

BOYS ATTENTION! Owing to demand, we 
have added a wireless table with cabinet cover to 
our list of knocked down furniture. Price from 
$1 up. Send for descriptive circular.. Stevenson 
Mfg. Co., 459 Tehama St.. San Francisco, Cal. 

YOU MLTST send stamped envelope for list of 
Wireless, Electrical, Mechanical goods. Carroll, 
Valley City, N.Dak. 



CEMENT — Best for Experimenters, sure sticker. 
Formula 50c. M. Blain, Barre, Vt. 

FOR SALE — Tested galena, 20c. per piece. 
Only silver accepted. Alvin Manternach, 17729 
Windward Rd., Cleveland, Ohio. 

THE POPULAR -APRIL SPECIAL extended 
thru May. Specially selected Audion FREE with 
every order for the ultra-sensitive "PARAGON" 
Amplifying Short Wave Receiver at $35. 15,000 



meter loose couplers, $11.50. Complete audion 
sets potentiometer equipt, for damped and un- 
damped signals, with "B" batteries and selected 
two filament bulb, $12.95. Send stamp for new 
catalog of QUALITY apparatus. Arthur B. 
Church, Lamoni, Iowa. 

SPECIAL — Oscilaudion bulbs for $4.75 each. 
Regenerative sets with detector $50. Undamped 
sets $40 complete. Let us know your needs and 
we will quote you. Radio Equipment Co., 104 
Fifth Ave., New York. Cable address RECO, 
N.Y. 

OBTAIN RESULTS with Stratton Apparatus: 
Tuner, $6 50. Send 2c stamp for price list. 
Stratton Electric Company, 215 Federal Street, 
Greenfield, Mass. 

LEUMITE — the new detector mineral, sensi- 
tive, staple. Send 25c. for generous guaranteed 
piece. Leumas Laboratories, 1261 Park Ave., New 
York. . 

ONLY $21.75? Gee! Paid $24 for mine! 
Where'd you get 'em ? From POWELL, agent 
for 36 companies. Send him return postal for 
bargain prices on any radio instrument made. 
216 Spruce, Takoma Park, Md. 

NEVER BEFORE! Galena detector, extremely 
sensitive, next to permanent, holds adjustment for 
weeks, 39c. prepaid. Lenzite detectors, $4.25. 
Kinderhook Electrical Agency, Kinderhook, N.Y. 

WOOD PARTS for 4.000 M. coupler finished 
in beautiful polished mahogany, size 18x7x7^4 in. 
While they last, with blue prints, 98c. Include 
postage for three pounds. Louis E. Schwab, 3708 
Brooklyn Ave., Cleveland, Ohio. 

VACUUM DETECTOR CIRCUITS— for bulb 
and tubular types, damped and undamped waves. 
Very latest. Complete with full descriptions, 50c. 
No stamps. L. H. Reiner, Bexley. Ohio. 

WIRELESS KITES— Manufacturers of kites of 
every description for every purpose. Do you 
want to hear from POZ? Write us, Dept. E., 
Frank G. Seyfang, 1465 Broadway, New York 
City. 

BAER ELECTRIC CO., Van Wert, Ohio- 
Special this month: 8 V., 18 W., Bell Transform- 
ers, rings 10 bells continuously, best quality, fine 
finish; each, $1.30. Satisfaction guaranteed; 
prompt; money refunded if not well pleased. 
Write for our price list of high quality supplies. 

RADIO QUESTIONS answered free. Send 2c. 
stamp for reply. Hinz Electrical Co., 234 Palmer 
Ave.. Syracuse, N Y. 

FOR SALE — Fifty Ford spark coils excellent 
for small sending station, $1 ; without vibrator, 
75c; large static machine, $5; also $26 melophone 
horn, $12. Write for list. Sidney Collisson, 
Keokuk, Iowa. 

GET BETTER RESULTS by using a sterling 
silver detector spring, 25c. prepaid. Guaranteed 
to be sterling silver. Address, Malcolm Burton, 
1157 Third Ave., Salt Lake City. Utah. 

QUALITY AND LOW PRICE combined. 
Judge for yourself by some of these prices: Au- 
dion panels with knob-controlled rheostats and 
high voltage batteries, $7. 5,000 meters cabinet 
set with combination perikon detector, $15. 
"Reco" 2-slide tuner set, $3.50. 12-inch 2-sIide 
tuner, $1.75. Send for literature. _ Lathe and 
specification work done. Radio Equipment Co., 
179 East 115th St, New York City. 



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MURDOCK 

NO. 55 



SENSIBLY 

PRICED 

SENSITIVE 

RADIO 

RECEIVERS 




GOOD ENOUGH 
FOR ANY STATION 




WHY PAY MORE? 



Description 



Real Radio Receivers 

THE BEST VALUE 
IN THE WORLD 




WILL YOU TRY A SET? 

Or will you simply read this advertisement and say, 

"It sounds well — but " 

There is no "BUT" in our GUARANTEE. We 
positively guarantee that BETTER 'PHONES CAN- 
NOT BE OBTAINED at these prices. We uncondi- 
tionally guarantee your satisfaction. 

GET A SET FOR TRIAL 

Send us a money order for the price of the set you 
select. It will be shipped to you at once. Try 
the set thoroughly for TWO WEEKS. Then, if you 
are dissatisfied with it in ANY way, send it back and 
your money will be refunded immediately. 

ORDER YOUR SET NOW 

Prices on all other MURDOCK APPARATUS have 
been advanced. Circular 16, showing NEW LIST 
PRICES, will be sent on application. 



Patented "SOLID" construction with 
absolutely permanent adjustment. Hard \A/li/l |tf| I I O T\ {T% |£ f\ 

rubber composition cases. Genuine copper § WIYI. %|. mUK&JUUrV OU. 

cod windings. Special thin diaphragms. 55 Carter Street, CHELSEA, MASS. 

Nickel-plated split head band. 5 foot mer- j§| 

cerized cord and special connection block. M 221 Second Street San FrancisCO 




iJVE minutes of actual practice prop- 
erly directed is worth more to a man 
than years and years of book study. 
Indeed, Actual Practice is the only train- 
ing of value, and graduates of New York 
Electrical School have proved themselves 
to be the only men that are fully qualified 
to satisfy EVERY demand of the Elec- 
trical Profession. 

At this "Learn by Doing" School a 
man acquires the art of Electrical Draft- 
ing; the best business methods and ex- 
perience in Electrical Contracting, together 
with the skill to install, operate and main- 
tain all systems for producing, transmit- 
ting and using electricity. A school for 
Old and Young. Individual instruction. 

Letters from Successful 
Men 

"I have done well since leaving school and 
am now Superintendent of the light, telephone 
and steam heat company here." 

"Ten months after I left you I was given 
charge of this station. J saved at least 3 
years by taking your course instead of work- 
ing up as an apprentice." 

"I have sole charge of all motors, lights, elec- 
trical devices and appliances, and in being able 
to hold this position 1 give all credit to the 
New York Electrical School and your personal 
interest in me, which until lately I did not 
realize would be so wonderfully beneficial to 



"We had no electrical experience before tak- 
ing your course and just one year since 
leaving school are working side by side with 
men of from five to ten years' experience." 

"Since graduating from your school, I have 
been able to hanrne successfully any problem 
that has come before me in my line of electri- 
cal work and I wish to express my_ feelings 
for the school and its methods of training." 

New York the Center 

We are located in the heart of New York- 
City and you can see the advantage of that. 
New York is the heart of everything electrical 
— there are big plants nearby, electrical ex- 
positions, libraries and facilities for good, 
quick work in an atmosphere of industry. 

A large number of our students come from 
other cities, from all over the United States. 
Thev realize the advantage of coming to New 
York to learn electricity. About 4,500 in all 
have gone out from our school into success. 
You can do the same. We believe that with 
us you can learn more thoroughly and more 
quickly than anywhere else because we give 
you practice. We teach you only what you 
use. 



And Now 



If. you have an ambition to make a name 
for yourself in the electrical field you will 
want" to join the New York Electrical • School. 
It will be an advantage to you to start at 
once. Then you should hurry to send for 
our 64-page book which tells you all about 
the school, with pictures of our equip- 
ment and students it work, and a full de- 
scription of the course. You need not hesi- 
tate to send for this book. It is FREE to 
everyone interested in electricity. It will not 
obligate you to send for it. Send the coupon 
or write us a letter. But write us now while 
you are thinking about the subject of elec- 
tricity. 

School open to visitors 9 A. M. to 9 P. M. 



New York Electrical School, 

29 W. 17th St., New York, N. Y. 

Please send FREE and without obligation to me your 64-page book. 



Name 



Address. 



is 




NEW YORK ELECTRICAL SCHOOL 
29 WEST 1715 ST., 

NEW YORK, N.Y. 



JUNE, 1917 - IS CENTS 




★ LARGEST CIRCULATION OF ANY ELECTRICAL PUBLICATION 



Th Is is the Electrical Age, and this wonderful new profession is calling yon. The 
demand for expert Electricians is greater every year and the salaries higher. Elec- 
tricity is truly the greatest motive power in the world, to-day, and now is the time to 
enter this profession. 



YOU CAN DO THIS 




You can earn $36 to $100 a week and more as an Expert Electrician. If you have a 
common school education 1 can train you in a few months at home. Big lighting and 
power companies, municipalities, and manufacturers are always seeking trained men to 
handle their Electrical problems. 

I Guarantee Satisfaction 

Every student receives our Sealed Guarantee Bond, which guarantees to return every penny of his 
money if he is not entirely satisfied. No other school has made this wonderful'- offer, but I know the 
success I have brought to hundreds of my students, and I know what I can do for any ambitious young 
man who will give me a little of his spare time each day 

FREE ELECTRICAL OUTFIT 



_ J^!A! LJTHJ S CO U PON 

Dept. 36, 

CHIEF ENGINEER. Chicago Engineering Works, 
439 Cass St., Chicago, Illinois. 

Without obligation on my part kindly send at once, fully prepaid, 
particulars of your complete Practical Home Study Course in Elec- 
tricity. 

Name 

Address 

Town State 



For the next 30 days I am giving - each student an Outfit of 
Electrical Testing Instruments, Tools, Electrical materials, and 
Motor absolutely Free. My instruction is by practical methods and 
this outfit is used in working out the lessons. Practical training 
with the theory makes perfect. I am Chief Engineer of the Chicago 
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the big jobs and hold them. 

If you are in real earnest I want to send you my new Book — 
"How to Become an Electrical Expert." It's free. No matter 
how many other schools you write to I want you to have my book 
— It's different because it's practical — Write today. 

CHIEF ENGINEER COOKE 

CHICAGO ENGINEERING WORKS 



Dept. 36 



439 CASS STREET, CHICAGO, ILL. 




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June, 1917 



THE ELECTRICAL EXPERIMENTER 



81 



AVIATION 

PRACTICAL AERONAUTICS BY MAIL 

%'Earn $50 to $500 a Week! 

TJTERE is the one inexhaustible gold mine of 
opportunity and here is the man who will 
lead you to it. It is the most extraordinary con- 
dition ever presented, owing to the sudden 
world-wide demand for aeroplanes. High 
class positions by the thousand calling for 
trained men — fame and fortune actually thrust 
at them. Salaries of from $50 to $500 a week are 
awaiting men who can fill these positions. And 
now, for the first time in history, a practical, home- 
study course in practical aeronautics is open to 
every man at a trifling expense. No matter what 
your occupation, you can prepare for a better posi- 
tion with big pay. Now is your opportunity. 

Enter a practically untrodden field — a new 
profession. Seize the opportunity that has burst upon the country with tremendous force. Hustle 
ahead with the rapid development of the aeroplane industry which is outrivaling that of automo- 
bile and motion picture, as the quick and sure road to financial independence. 




BUD MORRISS, Chief Instructor American School of Aviation 



Prepare NOW 

for these positions 

Aeronautical Engineer 
Aeronautical Instructor 
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Aeroplane Repairman 
Aeroplane Mechanic 
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Aeroplane Builder 



Conducted by Famous 
Aviators and 
Aeroplane Builders 

The Course has been prepared 
by men of international reputation. Mr. 
Bud Morriss, the well-known aviator, is Chief 
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the time and this is your opportunity to step 
right into fame and fortune. You are needed. 
Where there's a will here's the way. 



What Our Students Say: 

Mr. Stanfield Fries 

Fort Bliss, Tex. 
My estimation of the new course 
is excellent ; it could positively not 
be any better. 

Mr. Z. Purdy 

Shreveport, La. 
It is hard to believe that lessons 
on such a subject could be gotten up 
in such an interesting manner. 
Mr. Lloyd Royer 

Haigler, Neb. 
I can hardly thank you enough for 
the way you have personally taken 
up my enrollment. 

Mr. Mayne Eble 

Manistee, Mich. 
I believe I learn more from my 
lessons than an aviator who takes 
his first lesson with an airman in 
an aeroplane. 



Write Now for Our Great Offer a^.""" 

▼ of Aviation 

Send the coupon for full particulars of our remarkable special ♦ 431 so. Dearborn st. 
offer open to you now. Find out all about the marvelous opportunities f De P l - 8036 

that are opening in the Aviation game. This offer is the greatest stepping stone to ^ Chicago, III. 

bigger opportunities ever known. Write today for complete literature, all free ^ Gentlemen: Please send me free 
and prepaid. You are not obligated in any way. Do not waste time in thinking ^ and without obligation, full particu- 

about it. Act ! Send the coupon or a letter or a post card will do. Write at once. *7 la " of y° ur Cou Q rse l . n 1 P A% ctlc ! 1 Y, er °" 

1 1 ▼ nautics and your Special Offer to those 

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431 So. Dearborn Street 



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82 



THE ELECTRICAL EXPERIMENTER 



June, 1917 




FREE! 20 lessons 



Write me at once — TODAY! Just send the coupon or a postal. I will give you 
20 complete lessons in practical electricity FREE ! Think of it ! My personal and 

individual instruction for 20 lessons without a cent of cost to you if you act quick. No charge to you for 
these 20 lessons now or later. I make this sensational offer to secure a few more live students — to show, 
too, how quickly I can make you a Master Electrician no matter where you live, or what you do. But you 
must act at once! This offer closes in 23 days! Remember these free lessons are not merely sample 
lessons, but are a regular part of my fall and complete course in electricity. Send the coupon without 
delay— TODAY! 

Earn $2,500 to $4,000 a Year 

You can now qualify at home during your spare time, and without giving up 
your present position or occupation, for that most wonderful of all fields open to the 
ambitious man — the great and growing field of Electricity! Yes, no matter if you don't know a thing about 
electricity or never had a bit of electrical experience, I will take you in hand and make you an Expert 
Electrician so that you should easily earn $2,500 to $4,000 a year and more. And Til do it so quickly 
and with so little effort on your part, that you'll wonder how it was possible. No books or tools to buy. 

I Train You By Mail! Men Wanted 




Formerly with the General 
Electric Co.; former General 
Manager of company manu- 
facturing Jenney Electric Mo- 
tors; also formerly with Fair- 
banks, Morse & Co.; now Con- 
sulting Engineer and Director 
of the Wicks Electrical Insti- 
tute. 



I will instruct you personally — make the whole 
matter so simple for you that you. can't help but 
learn. When you have finished my instructions 
you are an Expert Electrician — ready to take a 
big paying job or start in for yourself. I show 
you not only how to do practical electrical work, 
but how to estimate on jobs so that you can take 
contracts at big profits. That's what it means 
to be trained by a man of my practical experience. 



Wherever you go there's always urgent demand 
for Expert Electricians and at big pay. That's 
because the watchword of the age is, "DO IT 
ELECTRICALLY." The field of electricity is 
broadening so fast that there's a big shortage of 
competent electricians. And the demand is in- 
creasing every day. 



Mail Coupon Today 



A. W. WICKS, E. E., Director, Wicks Electrical Institute 
81 W. Randolph St. Dept. 296 Chicago, 111. 

Without any obligation to me whatever, please send me full descrip- 
tion of your personal instructions in Electricity and particulars of your 
special offer of 20 of your lessons free. 

Name 

Street and No 

City State 



I 



YOU MUST ACT QUICK 

Mail coupon today. I want to hear from you immediately. _ Don't miss 
my offer of 20 personal lessons free. Remember this offer is strictly limited 
to 23 days. Write for all particulars at once. Here's your chance! No 
obligation to you. Send coupon or postal NOW! 

A. W. WICKS, E. E., Director 

Wicks Electrical Institute 

81 W. Randolph St., Dept. 296 Chicago, III. 



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ram 



233 FULTON STREET, NEW YORK 

Publisht by Experimenter Publishing Company, Inc. (H. Gernsback, President; S. Gernsback, Treasurer;) 233 Fulton Street, New York 



Vol.V Whole No. 50 



CONTENTS FOR JUNE, 1917 



No. 2 



ELECTROCUTING THE ENEMY Front Cover 

From a painting by George Wall 
ELECTRIC CROSSING SIGNAL OPERATED BY TRAIN'S 

WHISTLE By George Wall 85 

CHANCES FOR ELECTRICIANS IN THE NAVY 86 

^TALKING MOTION PICTURES VIA WIRELESS 87 

ELECTRICITY AND WATER TO RUN OUR AUTOS 88 

SHOOTING WITH ELECTRICITY By Hugo Gernsback 

ELECTRICITY'S AID TO WOMEN • 

POWERFUL HYDRO-ELECTRIC SALVAGE APPARATUS TO 
RAISE SUNKEN SHIPS. . .By H. Winfield Secor, Assoc. A.I.E.E. 
ELECTRO-DEPOSITED MIRRORS NOW USED FOR PHOTO- 
GRAPHIC WORK 

"JOE'S EXPERIMENT"— An electrical story by C. M. Adams 100 

ELECTRICITY AND LIFE By Dr. Frederick Finch Strong 104 

EXPERIMENTAL PHYSICS— LESSON 5, "HYDROSTATICS" 

By John J. Furia, A.B., M.A., F.K.S. 106 



90 - 
92 



hi 



97 



DENVER WIRELESS STATION WINS PRIZE LOVING CUP 

By W. H. Kirwan 

THE NAVAL RADIO OPERATOR— WHAT THE U. S. NAVY 

OFFERS TO RADIO MEN 

REMARKABLE RADIO OUTFIT BUILT BY GERMAN SPY... 

THE MARCONI TYPE "106" TUNER By Worth MacKnight 

THE HOW AND WHY OF RADIO APPARATUS— NO. 4 SPARK 

GAPS 113 

THE CLOCK CRAZE By Thomas Reed 114 

THE INFLUENCE OF LIGHT UPON THE CONTACT POTEN- 
TIAL OF SELENIUM AND OF CUPROUS OXID 

By E. H. Kennard and E. O. Dieterich 

HIGH FREQUENCY APPARATUS AND EXPERIMENTS 

By Hubert A. Mcllvaine 

THE PROBLEM OF USING THE ENERGY IN SUNLIGHT 

By Prof. I. Thornton Osmond 

EXPERIMENTAL CHEMISTRY— THIRTEENTH LESSON 

By Albert W. Wilsdon 123 



107 

108 
110 
112 



116 
117 



118 




Silencing America's Wireless 




W 



S all our readers are aware the United 
States Government, thru the Navy Depart- 
ment, has issued orders thruout the land to 
cause the immediate dismantling of all radio 
stations, 

whether large £■ ■■■■ "in n.nnnin.ui m.i . mil" 

or small, com- | 
mercial or amateur, send- 
ing or receiving. All 
aerials have been ordered 
dismantled and apparatus 
packed away. 

This action came as a 
great surprise to all pa- 
triotic amateurs, who for 
years past had been en- 
couraged by the Govern- 
ment and who were cer- 
tain that in time of war 
they would be allowed to 
"do their bit" with their 
outfits for the country. 

That the Government 
should silence all sending 
outfits was eminently 
proper, and we have as yet 
to hear the first complaint 
on that score. But why 
the receiving outfits should 
be dismantled by the Navy § 

Department is very puz- f, , ..„„ , mm „„„ murm u 

zling indeed. 

President Wilson's Executive Order is based upon 
the Radio Act of 1912, which act however, mentions 
nothing about closing receiving stations during the time 
of war. That purely receiving stations were considered 
harmless by the framers of the law, is best proved by 
the fact that such stations do not require to be licensed 
as do all sending stations. Moreover, in President Wil- 
sons's Executive Order of April 6, no mention is made 
of receiving stations. Indeed, the following passage 
strikes us as very significant : 

" and furthermore that all Radio Stations not nec- 
essary to the Government of the United States for Naval Com- 
munications may be closed for radio communication." 

The italics are ours. Particularly the one word MAY. 
In the same paragraph the President uses the command 
SHALL, while the word may does not imply that every 
radio station should be taken over by the Navy Depart- 
ment. Indeed, the longer we study the third paragraph 



EXECUTIVE ORDER 

HEREAS the Senate and House of Representatives of the 

1, have 
United 



United States of America, in Congress assembled, have 
declared that a state of war exists between the 



States and the Imperial German Government; and 

Whereas it is necessary to operate certain radio stations 
for radio communication by the Government and to close other 
radio stations not so operated, to insure the proper conduct of 
the war against the Imperial German Government and the 
successful termination thereof 

Now, therefore, it is ordered by virtue of authority vested 
in me by the Act to Regulate Radio Communication, approved 
August 13, 1912, that such radio stations within the jurisdic- 
tion of the United States as are required for Naval Communi- 
cations shall be taken over by the Government of the United 
States and used and controlled by it, to the exclusion of any 
other control or use; and, furthermore, that all radio stations 
not necessary to the Government of the L T nited States for 
Naval Communications may be closed for radio communication. 

The enforcement of this order is hereby delegated to the 
Secretary of the Navy, who is authorized and directed to take 
such action in the premises as to him may appear necessary. 

This order shall take effect from and after this date. 
The White House, 
6 April, 1917. 



of the President's Executive order, the more we become 
convinced that the closing of every amateur station, or 
even commercial stations, was remote from President 
Wilson's mind when he issued his order. 

In conformity to the 

i ni s Radio Act of 1912, the 

I President in time of war, 
may authorize any depart- 
ment of the Government 
to close all radio stations. 
But the President's order 
of April 6, was not to the 
Department of Commerce, 
which in the past con- 
trolled the nation's radio 
affairs, but to the Navy 
Department. Why? Be- 
cause the President, it 
seems to us, had only the 
radio communications of 
the Navy in mind. If, 
therefore, the Navy De- 
partment had caused the 
closing of all radio sta- 
tions, particularly sending 
stations along our sea 
borders, such action would 
have seemed perfectly log- 
|. ical. But why the Navy 
1 Department should wish 

.in.... mm"......!... „ ,„„„,„„, ii 1 1 ii mil to close stations a thousand 

miles removed from the 
sea borders, seems to us very puzzling. Furthermore, 
why all college radio stations, and those belonging to 
radio apparatus manufacturers as well, should be dis- 
mantled seems far fetched. Then there are cases like 
the one of the Lackawanna Railroad, which is one of the 
pioneer railroads in the United States to use wireless 
for train dispatching. Is it wise to dismantle such sta- 
tions on which the safety of passengers depends? 

We certainly have no quarrel with the Navy Depart- 
ment ; quite the contrary. We wish to help, but we sin- 
cerely do hope that its officials will soon find a way to 
modify its recent sweeping order. 

There are, indeed, encouraging signs already. Cer- 
tain commercial stations on the Pacific Coast have re- 
cently resumed operation, and it is to be hoped that 
amateurs will be allowed to operate their receiving sta- 
tions, at a not too distant future. H. Gernsback. 



(Signed) Woodrow Wilson. 




THE ELECTRICAL EXPERIMENTER is publisht on the 15th of each month at 23?. 
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THE ELECTRICAL EXPERIMENTER. Monthly. Entered as second-class matter at 
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83 



84 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



Now Is the Time to Rebuild Your Set 

and Install that 

Supersensitive Receiving Apparatus 

Owing to the present war conditions we can supply 
the Highest Grade Apparatus at very low prices 



Amplifying Coils 
Detectors 

Panel Sets 
Cabinet Sets 
Vacum Tubes 




Receiving Sets 

from 
$9.10 to $910.00 
Amplifiers 
and 

Oscillating Cabinets 
Complete 



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534 PACIFIC BUILDING :: :: :: SAN FRANCISCO, CALIF. 




AtLast! 

Electromagnetic waves of any 



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Oscillion Telegraph, capable of trans- 
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TYPE RJ11 — 2500 — 12000 METERS, $35.00 

THE DEFOREST LOADING INDUCTANCE 




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DeForest "Oscillion" 

( Oscillating- Audion) 

Generator of absolutely undamped oscillations of 
any frequency. Permits Radio Telephone speech 
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Laboratory and Research Work has a field utterly 
unfilled. Patents issued and pending. 

—MANUFACTURED BY 



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it is not a detector in any form. 



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TYPE VC4 — PRICE $20.00 

VARIABLE CONDENSER 

This Condenser is similar to our commercial type but is en- 
closed in an oak cabinet. It has 35 semi-circular aluminum 
plates. The maximum capacity is approximately .0025 M. F. 



You benefit by mentioning "The Electrical Experimenter" when ivriting to advertisers. 




THE. ELECTRICAL 
EXPERIMENTER 



H. GERN5BRCK editpr 

H. W. 5ECC7R dSSDCIftTE EDITC7R 



Vol. V. Whole No. 50 



June, 1917 



Number 2 



Electric Crossing Signal Operated by Train's Whistle 

By GEORGE WALL 



ANEW YORK genius has developed 
a clever idea for automatically 
sounding the alarm at railroad 
■ crossings, and whereby the alarm 
is controlled and actuated by the 
whistle of the approaching train itself. 
The accompanying illustration shows how 
the inventor proposes to mount a number 
of large size horns along the crossing- 
approaches, each horn being fitted with a 
super-sensitive electrical microphone, such 



the sensitive reed relay, the latter closes 
the proper circuits to a powerful electric 
siren installed at the top of the signal 
tower at the railroad crossing, as shown 
in the accompanying illustration and dia- 
gram of the elemental circuits. For night 
requirements, the alarm may consist of the 
electric siren and a powerful beam of light, 
both of which are projected out of the sig- 
nal horn. The siren is enabled to project 
its sound out into the horn past the incan- 



such as a slow-moving dash-pot attached 
to the sensitive relay, so that the relay 
could not open the siren and lamp circuits 
for a period of a minute or so ; thus mak- 
ing certain that the signal will sound until 
the train has past the crossing. The idea 
is, all in all, quite novel and possesses 
many other possibilities. 

The microphone has proven its worth in 
man}' difficult roles in industrial as well 
as military and naval operations. The sol- 




Instead of Having the Gateman Sound the Alarm at Railroad Crossings This Inventor Proposes That Sensitive 
Microphones be Erected Along the Crossing Approaches, the Sound of the Locomotive's Whistle Causing Them 
to Actuate a Relay Device Connected to an Automatic Crossing Signal. 



as used in the well-known Dictagraph. 
When the train whistle sounds for the 
crossing these microphones, scattered along 
a distance of several hundred feet on either 
side of it, pick up the sounds and are 
caused to control a sensitive relay device 
operating on the tuned-reed principle. The 
relay will thus respond with maximum effi- 
ciency to a certain whistle tone, as the 
vibrating reed armature fitted to it is 
selected to vibrate sympathetically with the 
dominant note of the locomotive whistle. 

When the approaching train's whistle has 
thus actuated the microphone and in turn 



descent lamp, as the latter is mounted on 
a perforated disc, thus allowing the sound 
waves to pass by it. The alarm tower may 
carry two or more of these combined elec- 
tric siren and lamp signals, and, as be- 
comes evident, the operation of the device 
is extremely efficient ; the alarm ceases as 
soon as the train has past the crossing. 

There are, of course, several details 
which are not shown in the accompanying 
view, which would be necessary in carry- 
ing out and applying the plan here pro- 
posed. For one thing there would have 
to be some form of time-element device 



diers in Europe have found the sensitive 
microphone of extreme value in listening 
to enemy sappers as they picked and 
shoveled a mine below the listeners. Again 
the French have been enabled to accurately 
locate and "spot" an enemy submarine off 
shore by. suitably disposing two or more 
specially tuned microphones along the coast 
at a known distance apart. Then by a sim- 
ple triangulation computation on a clever 
slide rule, the distance at J which the sub- 
marine happened to be, is readily found, 
and a fast patrol scout will be waiting for 
her when she arrives at the surface. 



86 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



Chances for Electricians in the Navy 




The U. S. Navy now 
offers excellent chances 
to ambitious young men 
who have a desire to 
learn a trade and 
learn it right. The na- 
val electrician has un- 
equaled opportunities 
for attaining an ex- 
ceedingly broad and 
substantial elec- 
trical knowledge, 
covering dyna- 
mos and mo- 
tors, wiring of all kinds, special and 
standard signaling systems, telephone 
systems, radio apparatus, and a host 
of other things with which the aver- 
age "land-lubber" may never become 
thoroly familiar. U. S. naval elec- 
tricians never need to fear that they 
can not land a job after their service 
in the navy is finished. 

Naval service offers many induce- 
ments to ambitious and spirited 
young men. Not only does it provide 
opportunities for free travel in many 
nearby and distant waters with 
changing scenes, but it furnishes ex- 
cellent training of high value in civil 



tors in use for ventilating blowers, ammu- 
nition hoists and conveyors, gun-pointing 
equipments, turret-turning machinery, and 
various other purposes. These motors are 
supplied thru special control apparatus from 
turbogenerators, engine-driven dynamos, 
motor-generators, etc. The lighting equip- 
ment includes incandescent and arc lamps, 
searchlights of the highest powers, special 
signal lamps, etc. Communication appara- 




consequently the training and experience 
received in their operation and main- 
tenance are of exceptional value to the 
electrician or radio operator in after life. 

Since the proper operation and care of 
all the varied electrical apparatus is essen- 
tial to the efficiency of the Navy, it is the 
practise to send all new recruits for this 
branch of the service to either of the two 
Navy Electrical Schools at the navy 

yards at Brooklyn, N. Y., and Mare 

Island (San Francisco), Cal. These 
schools provide instruction in two 
classes, general electrical work and 
radiotelegraphy. The length of the 
full course for both classes is eight 
months. Men specially proficient in 
the work pass thru this period in 
shorter time, depending on the knowl- 
edge and skill they show. All stu- 
dents, either recruits or men from 
the general service, may enter these 
schools at any time. In addition to 
the practical instruction imparted at 
the electrical and other naval trade 
schools and training stations, the men 
receive thruout their service aboard 
ship and elsewhere both academic and 
practical training to enable them to 
demonstrate their ability and to ad- 




Another View of the Electrical School 
at Mare Island, Calif., Class Receiving 
Instruction in Electrical Appliances, 
Including Electric Searchlights. 

pursuits at the conclusion of enlist- 
ment. It also furnishes steady, 
healthful work, free board of a 
wholesome nature, free lodging and 
clothing, and in addition provides 
pay, even during the period of train- 
ing, that can be practically all set 
aside for saving. The United States 
Navy pays its enlisted men better 
than any other national navy and 
in most lines more than the men 
could save and in some cases even 
more than they would receive in 
similar pursuits in civil life. Above 
all this it enables the men to render 
the highest patriotic service open to 
the citizens of any nation, that of 
defending the security of their coun- 
try in the first line of defense. 

The many uses of electricity aboard 
ship and in the naval stations have 
been steadily increasing. It is used 
not only for lighting and power 
service, but also for communication 
signaling, and even for cooking and 
ing. There are a multitude of electric 



Top: — View in Navy School, New York, Class in Interior 
Communication and Ship Control Apparatus. Below: — 
Testing Dynamos and Motors. 



and tits consists chiefly of telephones and radio- 
bak- telegraphic sets. Machinery and apparatus 
mo- in use in the Navy are of the highest types, 



Uncle Sam's Naval Men Receiving 
Training in the Operation of Electric 
Generators in the Navy School at 
Mare Island, Calif. 



vance in their chosen vocation. 

In order that a recruit may en- 
list for the electrical branch, he must 
have a knowledge of either general 
electricity, or be an operator of the 
Morse telegraph code or have suffi- 
cient foundation in radiotelegraphy to 
be competent to keep up with the 
class at the school. Electricians (gen- 
eral) must know the names and uses 
of the various parts of the dynamo 
and dynamo-driving engines and 
must be familiar with the ordinary 
types of switchboards and methods of 
wiring. Applicants for both classes 
must be able to write legibly, must 
understand elementary arithmetic and 
must be between the ages of 18 and 
25. All applicants must be citizens 
of the United States, either native 
or fully naturalized. 

Recruits meeting these require- 
ments are immediately transferred to 
the electrical school, where the course of in- 
struction comprises machine-shop work, 
(Continued on page 142) 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



87 



Talking Motion Pictures Via Wireless 



MANY of us have no doubt wit- 
nessed an exhibition of talking 
motion pictures, and numerous 
patents have been taken out on 
some very elaborate schemes in- 
tended to improve the efficiency of the ap- 
paratus involved in recording and repro- 
ducing the voice, as well as the figures of 
photoplay productions. 

One of the most novel ideas devised to- 
ward accomplishing this purpose is out- 
lined in a recent patent awarded to Wil- 
liam B. Vansize, of Brooklyn, N. Y. The 
accompanying illustration by our artist 
shows how the inventor proposes to utilize 
and apply the art of radio communication 
to the recording and reproduction of talk- 
ing motion pictures. In the first place, the 
studio stage is fitted with a metal floor, 
such as one covered with tin or sheet iron. 



diated thru a ground wire leading to metal 
plates (and points if necessary) on the 
heels of the actors, as shown, and also 
thru a miniature antenna comprising a 
series of tin-foil leaves which are sewn 
in the clothing in the manner indicated in 
the accompanying illustration. The radio 
apparatus is carried in the clothing, and 
the weight of each part distributed in the 
best manner possible. As will be noted 
the batteries are placed somewhat differ- 
ently in the case of a lady, as compared 
to a man. 

Thus far we see that whenever the ac- 
tors speak, that they will be radiating wire- 
less telephone currents, and these are in- 
tercepted or picked up by a larger radio 
antenna erected back of or just above the 
scenic settings of the studio stage in the 
manner illustrated. The stage antenna is 



a corresponding record of their voices on 
the moving steel wire of the telegra- 
phone, which has been explained in detail 
in previous issues of this journal. 

In brief, the telegraphone operates 
upon the principle that if a moving steel 
wire is past by the pole of an electro- 
magnet thru which electrical voice currents 
are circulating, then there will be local 
magnetisations set up in the steel wire 
corresponding to the voice fluctuations. If 
then we afterward pass this steel wire 
under another electro-magnet, the coil of 
which is connected to a telephone receiver, 
we can then hear the voice reproduced. 

The great problem confronting all in- 
ventors who take up talking motion pic- 
ture work is to accurately and practically 
synchronize the motion picture voice with 
the voice of the actor. This is the most 




T^ e °.1 e Great Problem m "Talking" Motion Pictures Lies in the Difficulty of Simultaneously Recording the Voice and the Scene. A 
New Method of Accomplishing This End Is Illustrated Here. Each Actor Carries a Radio-Telephone Transmitter on His Person. His Wire- 
less Love and Other Speeches Are Intercepted by a Stage Antenna, Connected to a Radio Receiving Set. This Set Is Connected to a 
Telegraphone Joined Mechanically to the Motion Picture Camera. Thus Synchronism Between Voice and Picture Is Established. 



This may be painted so as to give the 
effect of ±ile or carpet, and may have a 
few rugs scattered about to give an artis- 
tic stage setting. The small insert illus- 
tration shows how the inventor proposes 
to have each actor actually personify "a 
walking wireless station." In brief, each 
actor carries a complete wireless transmit- 
ting system on his person. When the ac- 
tor speaks, the voice waves affect a super- 
sensitive microphone hidden inside the coat 
or m the bodice, in the case of a woman. 
This microphone is connected to some 
form of miniature wireless transmitting ap- 
paratus, such as an Oscillion or vacuum 
bulb generator of radio currents. The voice 
fluctuations are caused to vary the cur- 
rent developed by the Oscillion, and these 
fluctuating, high frequency oscillations cor- 
responding of course to the voice, are ra- 



connected up thru suitable timing coils, 
with an oscillation or vacuum bulb de- 
vice, which is used in this case as a de- 
tector and amplifier of the received radio- 
telephonic currents. 

Now we have the actor's voice radiated 
by wireless from his own person, thence 
propagated thru space by etheric waves, 
and finally, we have them coming in thru 
the receiving circuit of the stationary radio 
detector. The secondary or auditory cir- 
cuit of the detector and amplifier is con- 
nected with the recording electro-magnets 
of a Poulsen telegraphone, mounted in- 
tact on the motion picture camera which 
is recording the scene photographically. 
Thus, as the photographer turns the handle 
on the motion picture camera, he not only 
records the physical movements of the ac- 
tors, but simultaneously he also obtains 



important problem, and by means of this 
wireless telephonic arrangement, as pro- 
posed by Mr. Vansize, it seems that it 
should become a simple matter to readily 
accomplish the purpose intended, viz., to 
record and reproduce faithfully a talking 
motion picture, and one in which the ac- 
tors' lips will not be moving about ten 
seconds after the voice is heard or vice 
versa. 

In practise a number of loud-speak- 
ing telephones are scattered about the mov- 
ing picture theatre, and as the operator 
cranks his machine, the telegraphone wire 
is unreeled at exactly the same speed. The 
impulses from the recorded telegraphone 
wire now are used to operate the loud 
talkers about the house, with the result 
that the audience sees and hears the ac- 
tors in a truly remarkable manner. 



88 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



Electricity and Water to Run Our Autos 



GASOLINE forms the nucleus of 
power in practically all automobile 
engines of the present day, and 
many inventors and chemists have 
expended considerable energy and 
money in an effort to find a satisfactory 
substitute for this all-important commodity, 
which has been rapidly and constantly in- 
creasing in cost. One of the latest attempts 
in this direction is that of Mr. Ernest E. 
Punches, who hails from Detroit, Michi- 
gan. 

"Give me a suitable tank containing a set 
of plates submerged in water and a source 
of electric current, and I will drive your 



close arrangement of the positively and 
negatively charged electrodes, the gas gen- 
eration is both rapid and efficient. 

As before mentioned the oxygen is liber- 
ated by suitable automatic valves, and the 
hydrogen is retained and past thru a mixing 
valve, similar to the usual carburetor used 
on all gasoline engines and which can be 
controlled from the driver's seat, follow- 
ing the standard practise in motor-car equip- 
ment. A suitable quantity of air is taken 
in thru the mixing valve, and which, when 
combined with the proper quantity of hy- 
drogen, forms a highly explosive gaseous 
compound. When this is fed into the en- 



load. The motor develops 45 h.p. on an 
average at this speed, and under full load, 
with a well worked in motor. The suction 
displacement per revolution is 244/2 equals 
112 cubic inches; equals .0648 cubic feet. 
Then at 3,000 revolutions per minute and 
assuming 100 per cent volumetric efficiency, 
the number of cubic feet drawn into the 
motor per minute is 3,000 times .0648, or 
194.5, and 60 times 194.5, or 11,670, is the 
number of cubic feet drawn into the motor, 
of mixture each hour, running at maximum 
speed and under full load. 

The gasoline entering into that mixture 
is 7 per cent by weight, and the amount by 



/NT/) HE M/JN/FOLDcJr 
TO Cr UNDER 



EIIR AND G/PS 

MIXER, 



MIXER 
^CONTROL 



DYN/PMO 




A Detroit Genius Claims to Have Solved the "Gasoline Substitute" Problem for Automobiles. He Utilizes a Very Simple Electrical Phenom- 
enon — That of "Electrolysis" or the Decomposition of Water by the Passage of An Electric Current Thru It. The Hydrogen Gas Evolved 
Is Mixed With Air and Past Into the Engine Cylinders. The Inventor States That It Is More Economical Than Gasoline Because of the 

Higher Explosive Value of the Hydrogen-Air Mixture. 



automobile engine without any gasoline 
whatsoever at reduced cost," says this san- 
guine inventor. 

The secret of this remarkable invention 
lies in the fact that if an electric current 
is past between two plates submerged in 
water, it decomposes the water, evolv- 
ing two gases, oxygen and hydrogen ; the 
oxygen accruing from this process is liber- 
ated, while the hydrogen is collected and 
when suitably mixed with a proper amount 
of air, it forms a highly explosive mixture 
when ignited in the automobile engine cylin- 
der. 

The accompanying illustration shows how 
the proposed water-electric gas-generating 
plant would be fitted to a motor-car, the 
special dynamo together with the decom- 
posing chamber and gas storage tank being 
placed with the engine under the same bon- 
net. The small Unipolar type dynamo is 
connected by suitable gears or driving 
chain to the timing gear on the crank shaft 
of the engine, and supplies a low voltage 
direct current. This current is past thru 
the electrolytic cell shown in the illustra- 
tion, alternate plates being charged posi- 
tively and negatively. The plates are pre- 
ferably perforated so as to promote circula- 
tion in the gas-generating cell, and by the 



gine cylinders and ignited by an electric 
spark, it produces a force many times more 
powerful than that obtained when gasoline 
vapor is used. Some of the hydrogen gas 
produced by the electrolytic cell (decompo- 
sition of water) is stored in a suitable tank 
under pressure, which makes it available 
for starting the car and emergency. The 
entire combination unit fits the carburetor 
side of the engine and is supported by the 
former manifold holding means and also 
by the frame of the auto chassis. It has 
been found by Mr. Punches from trial and 
also by calculation, that the hydrogen gas- 
generating outfit here described, and which 
it is proposed to substitute for gasoline, will 
require up to 5 per cent of the horse-power 
developed by the engine, this 5 per cent of 
the total engine horse-power being used to 
drive the decomposing current dynamo. 

There are 1,257.52 cubic feet of hydrogen 
gas in one cubic foot of water, the gas at 
atmospheric pressure, zero degree Centi- 
grade, and it will require 1,728 watts of 
electricity to decompose a cubic foot of 
water in one hour. Compare this with the 
following data, obtained from a Chalmers 
Motor Car Company engineer : — 

The maximum revolutions of the Chal- 
mers motor is 3,000 per minute under full 



volume will not depart far from the 7 per 
cent, as there is no great difference between 
the weight of air and gasoline vapor. So, 
in face of the fact that an explosion of 
hydrogen in a pure state, when mixed with 
air, is a thousand times as powerful, as is 
the same per cent of gasoline vapor and 
air, we shall be way above in figuring a 10 
per cent mixture of hydrogen gas with air. 
As 10 per cent of 11,670 is 1,167, the number 
of cubic feet of hydrogen, we must generate 
in an hour. Bearing in mind that there are 
1,257.52 cubic feet of hydrogen in a cubic 
foot of water, and that 1,728 watts will de- 
compose the cubic foot of water in an hour, 
and also that 746 into 1,728 goes about 2}4 
times, it is apparent that we will generate 
90.52 cubic feet of gas per hour more than 
the Chalmers motor can use at maximum 
speed, and under full load, taking less than 
5 per cent of the 45 h.p. to drive the decom- 
posing current generator. The inventor has 
demonstrated his invention before the entire 
engineering staff of the Tecla Electrical 
Laboratory of Detroit, Michigan. 

When it is understood that gasoline is 
simply a mechanical mixture of hydrogen 
and carbon gases and impurities, it will be 
seen that a mixture of pure hydrogen gas 
(Continued on page 145) 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



89 



OPTICAL DEVICE THAT RIVALS 
TELESCOPE IN STUDYING 
THE HEAVENS. 

An optical device, which is said to rival 
if not surpass the telescope in revealing 
the mysteries of the heavenly bodies was 
exhibited at a recent meeting of the Amer- 
ican Society of Mechanical Engineers in 
New York. The invention was exhibited 
by Dr. John A. Brashear, the grand old 
man of American astronomy, of Pittsburgh. 

"This instrument is called a diffracting 
grating," said Doctor Brashear, as he 
showed what looked like a rectangular 
piece of metal about 2 by 4 inches long 
that changed colors under the electric 
lights. "On the plane surface of this pol- 
ished plate, made accurate to one-tenth of 
a light wave, or within one-forty-five-thou- 
sandth of an inch, are ruled more than 
45,000 lines between which there is no 
greater error than one-two-millionth of an 
inch. 

"With this delicate piece of apparatus, 
made possible, first by rigorous scientific 
research; second, by the skill of the 
artisan ; third, by a knowledge of a vigor- 
ous care to avoid temperature changes, 
and, fourth, by the accuracy of the mech- 
anism, the astrophysicist has been able to 
tell the composition, temperature and dis- 
tance of the stars." 



GOVERNMENT TAKES OVER 
MARCONI STATIONS. 

The U. S. Government has availed it- 
self of the offer of the Marconi Wireless 



Todd, at Washington, will have charge of 
stations operated by the government. En- 
rollments will be made by commands of 
naval districts. t 



REVIVING THE CHAIN SHOT TO 
DESTROY RADIO AND OTHER 
AERIAL WIRES. 

An American inventor has recently pro- 
posed that the military and naval authori- 
ties revive a relic of warfare which was in 
vogue many years ago — this is nothing 
less than the generally well-known chain 
shot. In our grandfathers' and great-grand- 
fathers' day it was considered quite a 
nifty idea to tie one or more cannon balls 
together with an iron chain — thus, the name 
chain shot. The accompanying illustration 
shows a clever form of split projectile 
composed of three or more pieces divided 
in the manner shown, so that by means, 
of a time fuse or other arrangement, these 
pieces would fly thru the air as a solid 
projectile, and at the critical moment would 
explode and describe a path of consider- 
able width thru the atmosphere, and prov- 
ing, it would seem, of decided efficiency 




To Counteract the Poisonous Gas Fumes Blown Toward European Trench Rescuers Who 
Are Called Upon to Go Forth and Carry Prostrate Soldiers From Their Positions, They 
Have Guarded Themselves Against Being Overcome by a Novel Telephone Appliance At- 
tached to the Gas Defying Equipment. 



Telegraph Company of America, placing 
its staff and stations at its service and has 
taken over for the period of the war not 
only the Marconi stations but all other ra- 
dio stations for military purposes. The 
eligible operators will be enrolled in the 
government service. Stations not required 
will be closed. The trans-Pacific stations 
will continue handling commercial traffic, 
but under government supervision. No 
ship traffic will be permitted on the At- 
lantic and Gulf Coasts and the Great Lakes 
excepting for the government, but it will 




EUROPEAN SOLDIERS USE GAS 
MASKS FITTED WITH TELE- 
PHONES. 

The accompanying illustration shows in 
a marked manner one of the peculiar and 
particularly effective scientific devices 
brought out by the great European war. 

Needless to say this war of all wars has 
developed hundreds, even thousands, of new 
inventions of every conceivable character. 
First the Germans invented the gas ap- 
paratus by which they attempt to overcome 
their enemies in the trenches with clouds 
of noxious fumes, and here we have the 
answer to this challenge in the form of a 
gas mask or helmets, which are worn by 
the members of the trench rescue brigade, 
who are called upon to go forth and 
carry prostrate soldiers from their posi- 
tions where they may have fallen between 
the trenches, when overcome by the gas 
cloud. Each gas helmet and mask is fit- 
ted with a novel and specially designed 
telephone outfit, properly connected to a 
trailing wire leading back to the trench, 
so that the rescuers are able to telephone 
for aid without removing their helmets or 
apparatus. 



A New War Invention Is a Split "Chain Shell" That Automatically Explodes at a Given 
Range. It Should Prove Particularly Valuable In Destroying Radio Antennae and Other 

Wire Structures. 

in destroying radio antennae, and all other continue for the present on the Pacific, 
elevated wire structures such as telegraph Trans-Atlantic traffic via _ Glace Bay will 
and telephone wires, power transmission not be disturbed. The Director of Naval 
circuits, et cetera. Communications, Lieutenant Commander 



GOVERNMENT RADIO BILL GOES 
OVER. 

House leaders at Washington have de- 
cided definitely not to pass at this session 
the Administration bill for permanent Gov- 
ernment dictatorship over wireless appara- 
tus, unless the President specifically re- 
quests it. 

It was learned that the House Mer- 
chant Marine Committee believes the Presi- 
dent already has power enough over radio 
stations to prevent their use in time of 
war. 

The principal feature of the bill is its 
provision for eventual Government owner- 
ship of radio companies. This feature is 
not considered by the committee to be 
strictly war legislation. 



90 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



Shooting With Electricity 



YEARS ago, when the New York 
City elevated lines changed from 
steam to electricity, one of the ele- 
vated trains caught fire. An alarm 
was promptly turned in and in due 
time the firemen were on the spot. The 
stream from the high-pressure hose was 
played on the cars, and to prevent the fire 
from reaching the wooden structure on 
which the rails rested, as 
well as the wooden foot — — — . 
path, one of the firemen of 
necessity directed his 
stream on the third rail. 

The stars are not in- 
tended to indicate what 
happened and what that 
poor fireman saw ; rather 
they are meant to illustrate 
how long he remained un- 
conscious. As a matter of 
fact the man was almost 
electrocuted. Since that 
time firemen do not fight — ^— — — 
elevated fires unless they 
are assured that the power has been turned 
off. 

Now, the N. Y. Elevated Lines only carry 
500 volts direct current, but this pressure 
is sufficient to pass from the third rail 
line, then to the water of the fire hose, 
and from there into the metallic nozzle 
held by the fireman. Altho ordinary hy- 
drant water is a poor conductor, a 500-volt 
current nevertheless finds but little trouble 
in passing thru the stream of water and 
thence thru the body of the fireman, with 



By H. Gernsback 

liquid fire is sprayed upon the enemy, be- 
ing a parallel to the writer's scheme. While 
shooting flames over a distance of 50 feet 
or more has not proven a wonderful suc- 
cess, nevertheless the idea seems to have 
some merits. And if the Germans can shoot 
flames at us, why can't we return the com- 
pliment by shooting electricity at them? 
One is as easy as the other, with a few 



If AVE you ever stopt to consider that a fireman does not dare to let 
a stream of water from a nozzle strike an electric wire, carrying 
any appreciable potential, say a thousand volts or more, as he may be 
electrocuted. Proverbially speaking, it is a poor rule that will not work 
both ways. Hence we have the unique proposal by Mr. H. Gernsback, 
that we charge the enemy with highly electrified streams of acidulated 
water under high pressure. This unusual invention is not intended as a 
substitute for guns, but to supplement them. It represents one answer 
to the German's "Flammen Werfer" — Liquid fire. 



points in favor of the latter, it would seem. 

Briefly, the idea is as follows : Strapt to 
a soldier's back is a lead-lined metal tank 
carrying a solution of diluted sulfuric acid 
of about 1200° specific gravity. (A solution 
of chlorid of zinc or even ordinary salt 
water could be used.) By turning a knob 
on the outside of the tank a small quan- 
tity of zinc or iron filings is thrown into 
the acid and immediately hydrogen gas is 
evolved, causing considerable pressure in- 
side of the tank. This causes the acid 



lines) there is a 10-H.P. gas engine driv- 
ing a 5- to 8-H.P. Alternating Current 
Generator. The latter is connected to a 
step-up transformer delivering from 10,000 
to 15,000 volts. A thin but extremely well 
insulated cable connects with the nozzle 
carried by the soldier. This cable is con- 
nected to one side of the transformer ; 
the other pole is grounded to earth. If 
now the stream hits an 
— — — 2—— enemy soldier (who is not 
insulated from the 
ground), the high-tension 
current passing thru the 
stream of highly conduc- 
tive acid, runs thru the 
man's body and thence 
thru the earth, back to the 
transformer. In this case 
he probably will be elec- 
trocuted or else knocked 
senseless by the powerful 
current. Even standing on 

a piece of dry wood or a 

— ~~~ ~ ~~ — — stone will not help him, 
for the acid running 
down from his uniform will turn the wood 
or the stone into an excellent conductor 
and the enemy will almost certainly be ren- 
dered unconscious. Probably the most effi- 
cient way of utilizing the new scheme will 
be found in- directing the charged stream 
at a machine gun. The second the stream 
hits the metallic portion of the gun, the 
operators will be knocked unconscious or 
will even be killed. It is also understood 
that the entire electrocuting outfit, gaso- 
line engine, dynamo, transformer, acid tank 




The Germans Invented "Liquid Fire" With Which to Destroy the Enemy. Here Is An American Invention— Shooting the Enemy With 
Piercing, H igh- Pressure Acid-Water Streams Charged to An Electric Potential of 15,000 Volts. Trench Gasoline Engine, Electric Plants 
and Transformers Supply the Necessary Power. The Nozzles Are Heavily Insulated and the Soldiers Wear Heavy Rubber Shoes As 

Well As Gloves and Masks. 



the result that he is knocked unconscious. 
If the stream had been sea (salt) water, 
there remains little doubt but that the man 
would have been electrocuted instantly. 

Upon this principle the writer has based 
his idea of shooting electricity at an enemy, 
impracticable as the scheme sounds at first 
thought. Many murderous ideas, of course, 
have been advanced for trench warfare, 
the German Flammen Werfer, whereby 



to be forced out thru the hose attached 
to the tank and from the hose the acid 
passes thru the long nozzle carried by the 
soldier. The acid leaves in a fine stream, 
less than a quarter of an inch in diameter, 
and with a fairly calm atmosphere, it should 
carry from 75 to 100 feet. For most pur- 
poses, 50 feet however, will probably be- 
found sufficient. 
Now, back in the trench (or behind the 



and all the rest of the equipment could be 
placed in an armored car. In that case, 
the operators would not be exposed to ma- 
chine gun fire. 

When used by the soldier, however, it 
is self-evident that his equipment must be 
such that he himself will not be electro- 
cuted. To that effect he wears a special 
"high-tension" rubber shoe, capable of with- 
standing 20,000 volts.* ' Then too he uses 
"high-tension" rubber gloves, and in addi- 



• 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



91 



The Best Way to Aid the President 

By HOWARD H. GROSS, 
President Universal Military Training League 



AFIXT military policy which will 
protect the nation and strengthen 
her manhood is the special need 
of the hour. Each passing day 
demonstrates this. This League 
and its sponsors believe that in universal 
military training lies the na- 
tion's chief hope. They there- 
fore urge two things : 

First and foremost : Stand 
behind President Wilson in 
every way. He is bearing a 
tremendous burden. Assist 
him in all emergency meas- 
ures, whether financial, mili- 
tary or economic. 

Second : Use every influ- 
ence to impress upon our 
Senators and Representatives 
in Congress that emergency 
war measures now pending 
will not solve our military 
needs except temporarily. 
They may carry the country 
along for the present, but 
they will not do for the fu- 
ture. The most democratic 
program as a fixt military 
policy for the United States 
is that of universal compul- 
sory military training. It 
treats all alike, makes use of 
young men before they reach 
the age where their earning 
capacity is high and when 
they are yet unmarried, and 
gives them six months' intensive military 
training. Then it sends them back to work. 
These trained youth will form the backbone 
of a great, democratic citizen army. This 
is the only definite, simple and patriotic plan 
that will make America safe and ready. 

I earnestly hope that every American 
will stand by President Wilson and the 
Government officials who, with the Presi- 
dent, are bearing a gigantic responsibility. 
I have just returned from the national 
capital and I know and sense in a measure 
the weight that is taxing our silent and 
conservative Chief Executive. It would be 
shameful to see his plans for meeting this 
crisis defeated. Therefore, as should all 
citizens, I bespeak general co-operation 
with President Wilson in these mighty 
works. 



They are emergency measures, as he has 
said. This universal military training plan 
is supplementary to the President's emer- 
gency measures. It goes further and will 
last longer. While he is doing all that 
he can do safely to pilot the ship of state 





What Military Training Does For a Man. Compare the Two Recruits 
on the Left With the Two Erect Figures on the Right. They Are the 
"Same Men," Photographed Before and Ajter Being Trained for Five 
Months in the U. S. Army. 



thru the eddies just ahead, I ask all patri- 
otic citizens not only to strengthen his arm 
in this effort, but to aid the nation as a 
whole in supplementing the President's la- 
bors by the establishment of universal 
military and naval training. 

The benefits resulting from such a demo- 
cratic plan for raising an army in emer- 
gencies cannot be over-estimated. The last 
few weeks have shown how weak and 
futile other devices have been. The vol- 
unteer system is unfair, and because it is 
so thousands of young men who are as 
patriotic and loyal as the best in the land 
will not offer their services. They have 
come to realize that the strong, highest 
types of manhood go forward while the 
cowards and slackers only too gladly stay 
at home. The best blood goes to the front 



while the unpatriotic rejoice in secret in 
the opportunity to remain safe and sound 
at home, pile up money and have a good 
time. 

Such a false premium upon patriotism 
is not only disgraceful in a national mili- 
tary program, but it is de- 
cidedly uneconomical a n d 
wasteful. In nine cases out 
of ten the slackers are able- 
bodied, and u nder proper 
tutelage would make good 
soldiers, while the patriotic 
fellows who rush to the colors 
are the sort who are needed 
most to man the commercial 
and financial craft of the na- 
tion. The best brains will go 
into the ranks as privates and 
leave the sluggards at home 
to conduct the nation's af- 
fairs. This is fundamentally 
bad in a democracy. 

Selective conscription n o 
doubt may lie necessary at 
times, but it never will be 
popular. Universal military 
training, on the other hand, 
is, thru its very universality, 
plain, simple democracy. It 
says that all having the bless- 
ings of our institutions 
should, in time of need, con- 
tribute their aid to defending 
these institutions. It says, 
further, that the untrained 
soldier is so much "cannon fodder," and 
that the chances of the trained lad return- 
ing home in health from war are about 
three times greater than the untrained boy's. 

Therefore, in universal military training, 
the secret of our general military and naval 
needs for today, tomorrow and All Time 
is found. 

The Universal Military Training League 
makes special appeal to the people of the 
country to write their Congressmen to 
back President Wilson in all his emer- 
gency measures and to eradicate forever 
the doubt, uncertainty and weaknesses of 
present muddled military policy by es- 
tablishing in law a fixt plan for universal, 
compulsory military training and service. 

Stand by your President and strengthen 
your nation ! 



tion to this the nozzle is heavily insulated 
from his hands by means of a special in- 
sulator, as grafically shown on our front 
cover. The tank of course must be well 
insulated by soft rubber pads from the back 
o'f the operator. Thus equipt he is in little 
danger of being shocked by the current. 

Ia order to prevent the wind from driv- 
ing his own acid spray against the oper- 
ator's face, he is also equipt with a soft 
rubber mask, as illustrated on our front 
cover and on opposite page. 

From a humanitarian standpoint, the 
scheme is far ahead of the German flame 
shooter; sulfuric acid of 1250° does not 
blind, nor' does it destroy animal tissue, 
unless it remains in contact with it for a 
long period. Sprayed on the skin, but 
slightly itching results after a lapse of 



several minutes. On the other hand, the 
high.-tension current kills either outright, 
or otherwise puts the enemy out of the 
fighting for the time being, with little 
bad after-effects. The acid, plus elec- 
tricity, does not cause horrible burning 
wounds or burned off limbs as does the 
liquid ilame. 

' A_s with all war-schemes, the wise ones 
will now ask the usual question : What 
happens, if the enemy too uses the elec- 
trocuting apparatus? 

In answer the writer asks another ques- 
tion : What happens, if the enemy too 
uses liquid flames, or if the enemy too 
uses machine guns? 

*This shoe was described on page 24, May, 1917, 
issue of this journal. v 



AUXILIARY SIGNAL CORPS 
UP-TO-DATE. 

Perhaps the finest single auxiliary sig- 
nal corps possest by any army has been 
given to the LTnited States by the Amer- 
ican Telephone and Telegraph Company. 
About 500 engineers already have been 
selected and some of them have been 
sworn into army service. The differences 
between government pay and their salaries 
with the telephone companies will be paid 
by the latter. 

The corps will be made up of general 
plant and traffic engineers 'to plan, set up 
and operate telephone, telegraph and wire- 
less plants. If the regular force of the 
army proves to be too small, men also 
will be provided to assist in the wireless 
work. 



DATE OF ISSUE. — As many of our readers have recently become unduly agitated as to when they could obtain The Electrical 
Experimenter, we wish to state that the newsstands have the journal on sale between the fifteenth and the eighteenth of the month in 
the eastern part of the United States and. about the twentieth of the month west of the Mississippi River. Our subscribers should be in 
possession of their copies at these dates. Kindly bear in mind, however, that publications are not handled with the same dispatch by the 
Post Office as a letter. For this reason delays are frequent, therefore kindly be patient and do pot send us complaints as to non-arrival 
of your copy before the twenty-fifth of the month. 



92 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



Elec£ricf£yk AH f o Women 




Here We Have the Combination Electrio 
Stove. Strlpt for Action — Said Action 
Being That of Frying Eggs. And They 
Do Say Electrified Eggs Taste the Best. 




Who Can Remember Ironing Day Without 
Wishing There Wasn't Any Such Animal. 
But All Is Changed. Behold the Electric 
Ironer That Really Does Wonderful Work at 
4 Cents an Hour. Even the Chinaman Is 
Outdone. 



Do You Have to Polish Waxed Floors? This Back-Breaklng 
lask Is Now Accomplished In a Short Time and in a Highly 
tmcient Manner, by the Electric Motor Floor-Polisher Shown. 



Cook by Wire — Without Fire. The Com- 

bination Electric Table Stove Shown 
Above Enables You to Fry Eggs, Broil 
Chops. Make Toast. Boil Water — Yes. and 
It May Even Be Used as an Oven. 





Remember the Fellow Who Told the Waiter the 
Steak Was Too Rare? Said the Waiter— "We 
Cook by Electricity." "Well. Give That Steak 
Another Shock," Said the Patron. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



93 



Electricity's Place In Business 



ELECTRICITY SPELLS EFFI- 
CIENCY TO THE BOSS 
OF TO-DAY. 

Efficiency has reached a very important 
role in modern industry where the manu- 
facturer manifests a desire to obtain the 
maximum output of his plant with a mini- 
mum input — in other words — Efficiency. 
Various schemes have been promulgated 
in the direction of increasing efficiency in 
machinery and it was found that the best 
means which the manufacturer can em- 
ploy to determine the efficient output of 
his plant is to note the actual productive 
power of the individual output of each 
machine and employee. Schemes were in- 
troduced for this purpose, but the defects 
encountered in them were numerous and 
most of which had to be abandoned for 
the purpose for which they were made. 

The distinct need of an instrument for 
increasing the efficiency in productive plants 
grew more and more urgent, which caused 
a number of prominent engineers to study 
this rapidly growing problem. This work 
finally led to the development of an instru- 
ment called the Productograph, herewith 
illustrated and which has proved the solu- 
tion to this absorbing problem. The intro- 




The Business End of the Electric "Producto- 
graph" — the Instrument that Keeps Tally on 
the Daily Output of Each Worker in Shops 
and Factories. 

duction of this instrument was made pos- 
sible by the application of electricity. 

The first illustration shows the complete 
instrument which is stationed in the man- 
ager's or superintendent's office. It con- 
sists_ of a drum upon which a sheet of 
specially prepared paper is placed. Over 
this paper there are ten recording needle 
arms, which are actuated by electro-mag- 
nets ; these are located within the cabinet. 
Each needle is directed over the proper 
section of the paper and each needle is 
electrically connected to a single machine, 
of which the productive efficiency is to be 
found. The sections of the paper are longi- 
tudinally divided into 24 equal parts cor- 
responding to 24 hours. Each division is 
subdivided into minutes. The cylinder is 
rotated by means of an electric motor con- 
nected to a standard clock, operating a 
series of electrical contacts. Normally, 
when the needle arms are not acted on 
by the electro-magnet, which is connected 
to a special switch attached to the ma- 
chine the record of which is to be obtained, 
a straight line is made and every, time 
the machine is in operation it causes the 
switch to close the electrical circuit period- 
ically, which operates the needle arm and 
this in turn traces a curve on the paper. 




APPLYING PSYCHOLOGY WITH 
THE ELECTRIC "PSYCHOMETER." 

The latest device for testing speed and 
quality of human thought is the "Psychom- 
eter," which is 
an electrical appa- 
ratus now being 
used in San Fran- 
cisco, where it is 
being applied to 
accurately measure 
the degree of 
alertness in em- 
ployees in industrial 
establishments, a s 
well a s general 
mental alertness in 
all vocations. 

The Psychom- 
eter is operated by 
either alternating 
or direct current 
and may be at- 
tached to the base- 
board electric light 
socket. The clock- 
work attachments 
and electrical con- 
nections are oper- 
ated by pressing a 
simple telegraph 
key which is con- 
nected with the 
baseboard plug. 
The instrument is 
built in a grip and 
may be easily car- 
ried around. The readings are made by 
an electric light, which is mounted on the 
side of the small suit case. The instru- 
ment is an accurate gage of memory and 
measures speed and quality of thought 
to the fifth of a second, besides charting 
alertness and ability to react quickly in 
mechanical work and emergency situations. 

If the machine stops for any reason, the 
indication on the paper shows this and 
immediately gives the owner_ visual indi- 
cation of the fact. In addition to this 
equipment, an electro-magnetic counter 
is connected to the 
same circuit, which in- 
dicates the number of 
operations made by the 
machine. Thus, if this 
instrument is attached 
to a printing press, it 
will indicate exactly 
the number of printed 
sheets that the machine 
has made during a cer- 
tain p e r i od . Each 
needle has its corre- 
sponding counting in- 
strument and both are 
connected to a single 
switch. This particu- 
lar instrument here- 
with shown is adapt- 
able for ten machines. 

The second photo- 
graph shows the adopt- 
ion of this device in 
a clothing establish- 
ment, where it is used 
for checking up the 
number of coats made 
by each operative. 



measures, President Wilson has appointed 
a number of prominent engineers in the 
country to positions in the army. 

One of the appointments which will meet 



Photo from Press Illustrating Service. 
Prof. Miinsterberg Claimed to Be Able to Select the "Best" Ship 
Captains, Locomotive Engineers, Aviators, Etc. — All by Psychology. 
Here We See the "Psychometer" Being Used to Test the Mental 
Alertness of San Francisco Factory Employees. The World Do Move. 

with the most hearty approval of the elec- 
trical engineering profession is that of 
Paul M. Lincoln, Commercial Engineer of 
the Westinghouse Electric & Mfg. Com- 
pany, as Captain of the Engineer's Corps 
in the U. S. Army. 

Announcement has just been made of 
this appointment together with a number of 
other prominent engineers. 

Mr. Lincoln graduated from Ohio State 
University in 1892, and has for 24 years 
been associated with the Westinghouse 
Electric & Mfg. Company. He is a Past 
President of the American Institute of 




PROMINENT 
ELECTRICAL EN- 
GINEER BECOMES Here We See a Portable "Productograph." Connected to Each 
ARMY MAN Machine It Enables the Young Lady in the Foreground to Readily 

. . , * . Keep an Exact Record of Each Employee's Output. 

Appreciating the im- 
portance of securing Electrical Engineers, and has always taken 
the ability and training of the engineers of an active interest in the work of this as- 
the country for use in national defense sociation. 



94 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



SOUND RELEASES TOY DOG 
FROM ITS KENNEL. 

A very interesting toy has recently been 
introduced in the toy market and which 
is herewith illustrated. A similar toy was 
described in our June, 1916, issue, but the 
present one is of a simpler construction. 
The "Wireless Pup," as it is called, is 





Two Views of New "Wireless Pup" That Springs Out 
of His Kennel at the Sound of a Whistle, the Voice, or 
the Clap of the Hands. 



shown in Fig. 1 ; this shows the dog stand- 
ing outside of his kennel. The sensitive 
circuit-breaker and other apparatus are all 
placed within the kennel. This interesting 
and most amusing toy was originated and 
perfected by Mr. Christian Berger, a promi- 
nent physicist who has devoted most of 
his attention to developing scientific toys. 

The operation of this toy depends upon 
the opening of a delicate circuit-breaker 
by sounding a whistle or by the produc- 
tion of any other sound. This circuit- 
breaker is connected in series with a bat- 
tery and electro-magnet, which acts upon 
a flat metallic disc. This disc or plate is 
so arranged that when it is released by 
the electro-magnet, it will strike the dog, 
pushing him out of the kennel. The elec- 
trical circuit is only made when the flat 
disc is prest against the core of the mag- 
net, which holds the same to itself until 
the circuit-breaker is excited by sound 
waves. 

A detail photograph showing the various 
parts used in making up this toy is given 
at Fig. 2. The holding electro-magnet is 
seen at the left and consists of a core 
5^8-inch in length and ^-inch hi diameter; 
two insulated end pieces are placed on 
each end and the coil is wound with No. 
30 B. & S. enameled wire. The complete 
magnet is mounted on an iron frame, as 
shown. The small projection on top of 
the magnet is used to strengthen the mag- 
netic pull of the electro-magnet. The re- 
lease or discharge disc is fastened to this 
frame in such a way as to • permit the 
disc to spring forward when released by 
the electro-magnet. The complete arrange- 
ment is then mounted on a wooden base. 

The sound operated circuit-breaker is 
seen on the right. This consists of a 
rectangular metal box A, in which the sen- 
sitive parts are placed. The horizontal 
lever B is made from a No. 18 bare wire, 
bent as shown ; the ends are pivoted on a 



block of wood, the dimensions of which 
are those of the interior of the metal case. 
The lower part of the lever B, should 
touch lightly the metal surface of the case 
A, at point C. Of course this must be 
within the case. The complete circuit- 
breaker is placed behind the electro-mag- 
net frame, as noted in the assembled ap- 
paratus (center). Two sheets of metal are 
fastened to the base to form a sound col- 
lector. 

The connections of the toy "pup" is very 
simple, and is made as follows : One termi- 
nal from the electro-magnet is linked with 
the metal case of the circuit-breaker. The 
lever of the latter is terminated in a small 
flashlight battery and the opposite side of 
the battery is connected to the second lead 
from the magnet. When the "pup" is 
pushed into the kennel and against the 
tension of the spring disc, it is held by 
the energized electro-magnet. Then by 
making a sound 
such as by 
blowing a 
whistle, the cir- 
c u i t - breaker 
will be spurred 
up, thus open- 
ing m o m e n - 
tarily the cir- 
cuit which re- 
leases the 
spring disc, 
bouncing Mr. 
"Fido" out of 
the kennel. 

A trap drum- 
mer has dis- 
covered that 
electric lights 
i n s t a 1 1 ed in- 
side his drums 
keep the mois- 
ture out and makes the drumheads tight. 



AN ELECTRIC SELF-WAVING 
FLAG. 

One of the most talked of features at 
the Electric Railway Convention at Atlan- 



St. Patrick's Cathedral of Norwich, 
Conn., is lighted with six electric projec- 
tor units, which bring out the chancel arch 
and altar in beautiful relief. 



utton*! 

"Speakin' o' buttons," said Uncle Zeke, * 
Shifting his quid to the other cheek, 
"Speakin' o' buttons, I want to say, 
There's the beatenest kind, down New York 

way ; 

'Twaz in one o' them big hotels, by jing, 
That melts your dollars like snow in spring, 
That I see them buttons, along the wall, 
Right in a bunch ; mebbee six in all. 
'Twas gittin' too dark to see outdoors, 
An' I got to foolin' with them because 
There wuzn't much else fer me to do, 

i , When — Jiminy crick - 
ets ; before I knew, 
^ -_ I thought I had sot 
_ " ® ^ the house afire, 
" // '/'^ >Nv And I yelled as loud as 
/ / | V V \ our town crier, 
Till the folks came 
runnin', lickettycut! 
I told them what wuz 

the matter, but 
They didn't do nothin' 

but laffe an' joke, 
'Bout that dad blamed 
button I tried to 
poke, 

Then they showed me 
just how it worked, 
an' gee ! 

'Twas the cutest thing I ever see. 
Why, it made a blaze like a bonfire done! 
They said 'twuz invented by Eddy's son; 
I don't know just who Ed is, but say, 
His son is the feller that gits my pay!" 

By Pauline Frances Camp. 






This Flag Always Waves, Whether There Is 
a Breeze or Not. A Motor-driven Blower 
Pumps a Strong Draft of Air Up Thru the 
Hollow Mast, Which Accounts for the Mys- 
terious Effect Obtained. 



tic City, N. J., was a waving flag which 
fluttered from a 27-foot flagstaff in front 
of the General Electric Company's booth 
inside the spacious convention hall. Not a 
breath of air was stirring, yet the flag 
stood out on the pole as if a thirty-mile 
gale was blowing. The flag pole was of 
ordinary dimension and there was nothing 
visible to betray the source of the breeze. 
The base of the pole was surrounded with 
banked palms. It was only when visitors 
got very close to it that the scarcely audible 
hum of a motor gave a clue to the source 
of the breeze. 

The whole device is really quite simple 
in construction and easily explained, for the 
flagpole is a metal tube and an electric 
blower at the base shoots a strong current 
of air thru the flagstaff. The air escapes 
thru perforations in the top of the flagpole 
and imparts a waving motion to the flag. 



PROCESS FOR DRAWING LAMP 
FILAMENTS. 

A process for cold-drawn metallic fila- 
ments has recently been patented by Mr. 
K. Nishimoto, of Tokyo. Forming at first 
a consolidated stick of mixture of tung- 
sten and a small proportion of thorium, 
an alloy is obtained by uniformly heating 
the mixture at a sintering temperature and 
then gradually keeping its temperature at 
dull red heat. The consolidated stick is 
then subjected to repeated hammering or 
rolling until it becomes so ductile that it 
may be hammered into bars, rolled into 
sheets or drawn thru dies into wires, much 
like the metals which are commonly treated 
in this manner at ordinary temperature. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



95 



Powerful Hydro - Electric Salvage Apparatus to Raise 



Sunken Ships 

By H. Winfield Secor, Assoc. A 



POSSIBLY more than one enterpris- 
ing inventor of to-day has conjec- 
tured on the problem of raising 
some, if not all, of the hundreds of 
torpedoed steamers which lie scat- 
tered along the European coast in compara- 
tively shallow water, not to mention the" 
many sunken ships lying within the coast 
boundaries of our own country. It is not 
often that we hear of a sunken ship being 
floated and brought 
into dry-dock for 
the reason that the 
cost of performing 
such an engineering 
feat is generally 
prohibitive, and 
also in many in- 
stances, the prob- 
lem of raising the 
sunken vessel at all 
has practically been 
beyond solution. 

Now comes an 
American inventor, 
of Swedish birth, 
one Mr. Carl Lin- 
quist of New York, 
and formerly of the 
Swedish Navy, who 
has devised a re- 
markable new 
scheme for raising 
sunken ships of no 
matter what size, as 
long as they do not 
lie in too great a 
depth of water, and 
which idea he in- 
tends commercializ- 
ing at an early date. 

It goes without 
saying that if Mr. 
Linquist's idea, as 
outlined herewith, 
proves feasible and 
successful, that he 
will find plenty of 
work for several years to come. 

The inventor's idea involves the use of 
two or more telescopic cylinders or cham- 
bers as shown in the accompanying illustra- 
tion, which are attached thru massive uni- 
versal joints at their bases to the large 
horizontal submerging chambers or "feet" 
which rest on the bed of the ocean or lake. 
In the first place, it is of course paramount 
that the exact location of the sunken vessel 
be known. Having this information, the 
salvage expedition sets out from the near- 
est port with the necessary number of these 
large collapsible cylinders with their at- 
tached base members ( or "Forts" as their 
inventor calls them). The vertical cylin- 
ders shown lie horizontally, and as do also 
the base members, which are made to float, 
and the vertical and horizontal sections 
double up like a jack-knife, permitting the 
several units of this equipment to be towed 
by tug boats to the scene of the wreck. 

The present plans of the inventor con- 
sider that salvage operations may be suc- 
cessfully carried on for any size vessel in 
depths of water up to three hundred feet, 
and where necessary four to eight or even 
more of the raising cylinders are employed, 
placing an equal number of them on each 
side of the sunken ship. 

Supposing that several units of the sal- 
vage equipment are ready and floated to 



I. E. E. 



the position where they are to be used, the 
engineers then proceed to fill the base mem- 
ber with water causing it to sink. As it 
does so, the upright cylinder naturally as- 
sumes a vertical position, and moreover the 
base member obtains a very powerful hold 
on the bed of the ocean or harbor by "sand- 
suction," besides the heavy water pressure 
bearing down on its outer surface. A num- 
ber of strong cables are let down in the 




After the War There Will Be Thousands of Vessels Lying on the Oceans' Beds. If Only a 
Fraction of These Can Be Floated and Repaired, Think What It Will Mean to Commerce. 
A New Invention Intended to Accomplish This Purpose Is Illustrated Here and Involves 
the Use of Two or More Powerful Cylinders Which, as They Are Emptied of Water and 
Made More and More Buoyant, Finally Exert Sufficient Upward Pull on the Cables to 

Lift the Vessel. 



water, and with the aid of an operator in- 
side the inner pontoon who directs the 
work, these cables are swept under the hull 
of the sunken vessel. When all of the 
cables have been properly placed, the en- 
gineers are ready to begin operations for 
raising the wreck. Here is where the re- 
markable genius of Mr. Linquist comes into 
play, for he does not attempt to raise the 
ship by means of steam or any other form 
of engine. He has called upon Dame Na- 
ture herself to furnish the wherewithal to 
raise any ship, no matter what the size. In 
brief, what he does is this : — 

The upper telescopic and movable cylin- 
ders rising within the vertical floating 
chambers and guides, they are allowed to 
fill with water from the ocean itself, and 
as will be seen these will then sink to any 
required depth. When they have submerged 
until their upper structure is just above the 
water, the valves are closed, and by means 
of powerful electric pumps (in case the 
operations take place a considerable dis- 
tance from shore, gasoline engine-driven 
pumps are available), the water within the 
movable upper cylinders is rapidly pumped 
out. But a moment's reflection is required 
to at once see that these upper cylinders 
will naturally become steadily more and 
more buoyant, and providing they are built 
of the proper size for the work in hand, 



they will exert a tremendous lifting power 
of thousands of tons. After these cylin- 
ders have gone up a suitable distance the 
lines are caught by the stationary vertical 
member and the ship is thus held while the 
floating cylinders re-fill and take a new 
bite ; the same operation is then repeated to 
the surface. 

Mr. Linquist intends building these cylin- 
ders, not of steel but of narrow strips of 
wood several inches 
thick, or steel may 
be used in certain 
cases. The wood 
strips are tongued 
and grooved and 
caulked and are held 
in shape by steel 
bands. The pressure 
of the water on the 
outside of the cylin- 
ders will in conse- 
quence tend to al- 
ways tighten them, 
as becomes evident. 

The inventor has 
broached and dem- 
onstrated by means 
of models, his 
unique idea to a 
large number of 
sea-going men, in- 
cluding commanders 
of salvage squad- 
rons, and also to a 
number of naval 
men, and has re- 
ceived unqualified 
recommenda- 
tions from these 
men, who should be 
qualified to judge as 
to the efficiency or 
inefficiency of such 
a device if anyone 
could. Not only is 
this idea of consid- 
erable promise and 



utilification in salvaging sunken vessels in 
times of peace, but it possesses according 
to Mr. Linquist, several valuable naval fea- 
tures. For one thing he has suggested that 
one of these hydrostatic units would prove 
very efficacious in the role of a "Submarine 
Base," the outfit being anchored several 
hundred miles from shore stations if de- 
sirable. Also they would serve as a resting 
place for the crew. 

The inner cylinder would have a large 
capacity for the storage of oil and gaso- 
line for submarines, and in the event of 
being sighted by a hostile war vessel, the 
upper cylinder and super-structure could be 
submerged so as to be invisible, and the in- 
ventor claims that no force, even the ocean 
itself, cannot budge his suction foot mem- 
ber an inch, once it has got its grip on the 
bed of the ocean by natural "sand-suction," 
and besides most of the floating membei 
lies in calm water, the action of the waves 
not reaching very deep. A means is pro- 
vided for releasing this all-powerful grip 
upon the ocean-bed when it becomes de- 
sirable to move the unit to some other lo- 
cation. .U. S. Naval Officers have been 
favorably imprest with this idea. 

In closing, it is interesting to note that 
another valuable possibility of this device 
is that of releasing stranded vessels which 
(Continued on page 144) 



AMONG the hundreds of new devices and appliances publisht monthly in The Electrical Experimenter, there are several, as 
a rule, which interest you. Full information on these subjects, as well as the name of the manufacturer, will be gladly 
furnisht to you, free of charge, by addressing our Technical Information Bureau. 



96 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



ELECTRICITY NOW ROCKS THE 
CRADLE. 

"The hand that rocks the cradle, rules 
the world" — runs an age old proverb, and, 
albeit, one that embodies more truth than 
fiction nowadays, perhaps, when we have 




A Chicago Genius Has Evolved a Clever Combination — a Baby 
Carriage Plus an Electric Motor and Part of a Small Grinder 
Reduction Gear. Result — No More Pushing the Baby Carriage 
Back and Forth. We'll Bet His Wife Is a Suffragette! 



and sawed a slot into it for a distance of a 
foot at the other end, this slot passing thru 
a hole bored in it of the size of the wood 
handle on the grinding mechanism, which is 
inserted thru the hole and then the two 
parts of the connecting rod brought to- 
gether upon it by means of a little bolt. 

Only a minute is re- 
quired to trundle the 
little wooden frame 
to any place in the 
house, one end being 
provided with little 
casters, also shown in 
the picture. The mo- 
tor can be attached to 
any lamp socket by 
means of a flexible 
attachment cord, and 
in this circuit near 
one of the binding 
posts on the motor 
Mr. Joleen has in- 
serted a small push- 
button switch for 
starting and stopping 
the motor. When the 
carriage is set on its 
yHP 1 little track the con- 

kSSfUBZ^^k. necting rod can be in- 

v^fH^^ stantaneously con- 

nected by simply lay- 
ing it on the bar so 
that the slot engages 
the latter, and the ap- 
paratus is ready 'to 
work. Who will be 
so kind as to invent 
an electric bottle 
feeder? Next! 



the suffrage party to conjure with. But 
the "stiffs" will have to look to their lau- 
rels, for here is an electric motor that rocks 
the cradle. Yes, and it doesn't object to 
twins or triplets. "Come one, come all," is 
its motto. 

This device not only will rock the cradle 
but will trundle a baby carriage back and 
forth on a little track, with a gentle, sooth- 
ing motion which may be better than the 
traditional cradle rocking movements. The 
device was made for private use by Mr. 
Nels Joleen, of Chicago. 

Mr. Joleen's little girl required so much 
of Mrs. Joleen's time that the resourceful 
father decided that as long as the gentle 
pushing to and fro of the baby carriage 
seemed to be a sovereign pacifier on all 
occasions, he would provide something 
which would perform the mechanical work, 
leaving the mother free to go about her 
other duties. 

Accordingly, Mr. Joleen made the little 
wooden frame, shown under the wheels of 
the carriage ; attached thereto a grinding 
wheel designed to be operated by hand, 
something which he had in the house for 
sharpening tools ; and then attached a small 
motor of the kind which was once used as 
a sewing machine motor, accomplishing the 
connection by means of a belt from a very 
small pulley on the axle to the perifery of 
the grinding wheel. The driving pulley had 
to be made so small that he simply cut a 
short section of a broom handle, bored a 
hole thru the center, and fastened it on 
with a small set-screw. The gearing in the 
grinding wheel mechanism, originally in- 
tended to speed up the grinding wheel with 
reference to the number of revolutions per- 
formed by the handle, now works just the 
other way to all intents and purposes, as 
the speed of the motor must be reduced to 
the slow circular movement desired. 

In order to transmit this motion and at 
the same time translate it into a back and 
forth movement Mr. Joleen then took a 
small piece of wood about three feet long, 
notched it at one end where it rests over a 
brace underneath the body of the carriage, 



SEWING MACHINE PLUS MOTOR, 
SAVES LABOR. 

The sewing machine was one of the first 
household appliances to be equipt with an 




This Electric Sewing Machine Motor Drops 
Out of Sight with the Head and Drives Very 
Efficiently Owing to Its Spring Base 
Mounting, 

electric motor. The first motors employed 
were just the ordinary type, but later de- 
signs have resulted in the development of 
a motor having necessary speed control for 
use solely on sewing machines, and the effi- 
ciency and operating features of such 
motors have been greatly improved. 

The latest and most desirable features 
are to be found in the special motor shown 
in the accompanying illustration. 

This type can be readily attached to any 
make of stationary or drop-head sewing 
machine, new or old, with the exception of 
a few obsolete models. When not in use 
the motor, if mounted on a stationary head 
machine, can be pushed back out of the 
way and the cover put on, or dropt with 
the head if used on modern types of drop- 



head machines. When desired, however, 
the motor can be removed readily by 
loosening one thumb screw, as it is light 
and portable. 

The speed regulator is slipt on the 
treadle and held by a spring, making the 
mounting exceedingly simple. The operat- 
ing chain is attached to the metal frame- 
work directly above the controller and 
pulled taut. 

The regulator is light and substantial. 
The case is made of prest steel and the 
principle of operation is entirely new. 
When there is no pressure on the treadle 
the circuit is open. With a slight pressure 
on the treadle a contact is made and as a 
greater pressure is applied the resistance 
is cut out turn by turn. By varying the 
pressure, one stitch, or several hundred 
stitches a minute can be taken. There are 
approximately 100 steps in the controller, 
giving a corresponding number of speeds. 

When folding up the machine it is only 
necessary to loosen the belt, disconnect the 
plug, and swing the motor around under 
the head. Felt pads underneath the base 
prevent the motor from scratching the fin- 
ish of the machine. 

The motor itself is out of the way when 
operating. This leaves both sides of the 
machine table clear so that the operator 
can use this space for sewing material. 

The outfit, which is compact and light, 
consists of a small motor which operates 
on either alternating or direct current, 
mounted on a nickel-plated base, a speed 
regulator with operating chain and ten feet 
of cord and plug, and a round leather belt. 
The weight, including the speed regulator, 
is only 7 pounds. 

The cost of operating this motor is so 
small as to be almost negligible. At 10 
cents per kilowatt hour, it costs less than 
one cent an hour or less than it takes to 
run the ordinary incandescent lamp. 



THE ELECTRIC TEA KETTLE IS 
HERE. 

The recognized convenience and growing 
popularity of heating small quantities of 
water by electricity has prompted the de- 
velopment of the electric tea kettle illus- 
trated. 

The successful operation of an electric 
tea kettle depends largely upon the type of 
heating element — method of application of 
heat, etc. The heating element here used 
is of the submerged type, located on the 
bottom of the tea kettle and when in use 
is entirely surrounded by water. Thus all 
heat generated is efficiently utilized. 

The tea kettle has a capacity of 2^ pints, 
is made of drawn copper, spun into shape; 
spout of white metal ; has bail handle, sides 
of which are steel, grip made of ebonized 




Here We Have the Electric Tea Ket- 
tle. Hot Water When You Want It 
and Where You Want It Is Now an 
Actual Fact. 



wood comfortably shaped for convenient 
pouring. The lid has no hinge to come off 
—locks on securely. The knob forms an 
integral part of the metal lid. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



97 



THE PROPERTIES AND COMMER- 
CIAL APPLICATIONS OF 
SELENIUM. 

By W. F. Alder. 

Selenium was discovered by the Swedish 
scientist, Berzelius, in 1817 as a by-product 
of the distillation of sulfuric acid from 
iron pyrites. It has an atomic weight of 
79.5 specific gravity in its electrical con- 
ducting form of 4,788, its va- 
por sp. gr., at 2,588°F., being 
5.68. 

Selenium, like sulfur, with 
which it is isomorphous, ex- 
ists in different allotropic 
forms, three of which are as 
follows : 

(1) Amorphous Selenium is 
formed as a finely divided 
brick-red powder, when a so- 
lution of selenous acid is pre- 
cipitated by sulfur dioxid gas, 
or when the acid is reduced by 
suitable agents. Amorphous 
selenium has a sp. # gr. of 4.26 
and is soluble in" carbon di- 
sulfide. 

(2) (a) Semi-colloidal red 
amorphous Selenium is 

formed when solutions of dextrose and 
selenous or selenic acid are gently heated 
together. At 100°C. it is partially trans- 
formed into ordinary black Selenium. 

(b) Colloidal Selenium can be obtained 
in a blood-red solution by an aqueous solu- 
tion of the red precipitate obtained by ihe 
reduction of Se 2 . 

(3) Vitreous Selenium is formed when 
the amorphous variety is heated to 218° 
C. and then suddenly cooled when it forms 
a brittle, black, glassy mass, soluble in car- 
bon disulfide having a sp. gr. of 4.28. 

All three of the above forms have so 
high an electrical resistance that they may 
be regarded as non-conductors. 

The Selenium as used in the electrical 
arts belongs to still another modification, 
viz., the crystalline or metallics state ; 
metallic selenium is obtained when the 
melted vitreous variety is cooled to 210° 
C, and then maintained at that tempera- 
ture for some time. , 

The gray crystalline modification which 
makes possible the selenium cell occurs in 
two forms, vi7 

(1) Round gran- 
ular crystals, stable 
at 140°C, an insu- 
lator in the dark 
and not very sensi- 
tive to changes in 
light intensity. 

(2) Which is 
readily formed 
when the above 
granular form is 
heated to 200° C. In 
this form it is a rel- 
atively good con- 
ductor. It will, 
however, instantly 
respond to succeed- 
ing exposures. The 
general belief, also 
erroneous, seems 
to be that the short- 
est wave lengths, 
i.e., the violet, are 
the ones which have 
t h e most pro- 
nounced effect upon 
the conductivity of 
Selenium, but ex- 
haustive research 

has proven that the waves having the great- 
est activity for increasing the conductivity 
have a length of over 5,000 units. 

The writer encountered innumerable 
difficulties which were, however, overcome 
in the type of cell illustrated herewith. 



Electro-Deposited Mirrors Now Used for 
Photographic Work 



IN splitting the light from a certain 
source, the problem of dividing the 
rays in definite portions may strike 
one at first thought as an exceedingly 
difficult task. In certain kinds of pho- 
tographic and optical work, however, it is 




voltage, however, is very high and is stept 
up by a transformer from a value of 156 
volts to 5,000 volts. 

As soon as the current is turned on a 
pink glow is noticeable in the jar. Just 
above the thin metal cathode, however, 
there is a certain dark region which is 
called the Crooke's dark space. The action 
of the current causes minute particles of 
metal to leave the cathode and to be de- 
posited on the glass plate which is placed 
just at the edge of the Crooke's dark space, 
where the metal is most cohesively depos- 



Fig. 3 (At Left). Jar for Making 11-inch Partly 
Transparent Mirrors. The Cathode Is at the Bottom 
and Consists of a Thin Sheet of Gold or Platinum- 
iridium Alloy. The Glass Plate to be Coated Is in a 
Plane Parallel to the Cathode. 

Fig. 1 (Below). Arrangement of Apparatus for Electro- 
plating Partly Transparent Mirrors in a Vacuum, the 
Smaller Jar Being in Operation. 




Selenium Cell in 
Vacuum. 




very essential to divide the rays in such a 
manner that one portion of the light will 
go in one direction and the remaining por- 
tion in one or more other directions. Part- 
ly transparent mirrors are used for the pur- 
pose, and in order that the precise division 
of light may be known beforehand, the 
thickness of the thin layer of metal which 
is deposited on a plate of glass to form the 
mirror must be exactly known. 

In Fig. 1 is shown the apparatus devel- 
oped in the research laboratory of one of 
the leading camera manufacturers for use 
in making mirrors of different degrees of 
transparencies employed in certain impor- 
tant photographic experiments. Two in- 
verted glass bell jars are shown, each of 
which is connected to a vacuum-pump sys- 
tem. By means of this arrangement the air 
pressure inside the jars is reduced to a 
scant millimeter. This is done because in 
a rarefied gas the passage of electricity 
from the cathode, the terminal at the bot- 
tom of each jar, to the anode — the upper 
terminal, is greatly facilitated. The ca- 
thode consists of a very thin sheet of metal, 
which usually is of gold or an alloy of 
platinum and iridium. A short distance 
above this sheet of metal in a plane paral- 
lel to it ; the glass plate to be coated is 
placed on glass pillars as shown. 

The larger jar is 16 inches in diameter 
and 11 inches high and is used for coating 
mirrors 11 inches square. With the air ex- 
hausted the atmospheric pressure on this 
jar (about 15 pounds per square inch) 
mounts up to approximately five tons. 
The current is measured in thou- 
sandths of an ampere (milliamperes). The 



ited. With the current constant it is only 
necessary to record the time of operation ; 
the amount of metal deposited can then be 
easily determined, since it will, according 
to Faraday's law, be proportional to the 
time and current. 

In Fig. 2 is shown a set of interesting 
curves obtained in a typical run with a 




M// Amps. - Minute 
Fig. 2. Curves Showing Reflecting Power at 
45 Degrees Incidence and Percentage of 
Metal Deposited and Light Transmitted for 
Platinum-iridium Mirror With Varying Prod- 
ucts of Time and Current. 

cathode of 70 per cent platinum and 30 
per cent iridium, measuring 120 millimeters 
by 120 millimeters by 0.1 millimeter. These 
curves show the reflecting power at 45 
degrees incidence and the percentage of 
light transmitted and metal deposited on a 
unit of area for varying products of cur- 
rent and time. It was found that a mirror 
whose transmission was equal to its re- 
flection required a deposit of 3.4 milli- 
grams per square decimeter. 
Photos courtesy of Eastman Kodak Co. 



9 8 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



A New Optical Pyrometer 



The new pyrometer here shown is a prac- 
tical, convenient, and at the same time, ac- 
curate instrument, which can be success- 
fully used by unskilled workmen. Temper- 
atures from 700°C. upwards are read di- 
rectly upon clear, open scales. Owing to 
the rapidity with which readings can be 



New English Electrical Tempera- 
ture Measuring Instrument, Based 
on the Comparison of a Beam of 
Monochromatic Light from the 
Heated Body with a Similar Beam 
from an Incandescent Lamp. 




taken, and the ease of sighting upon small 
objects, this pyrometer is particularly suit- 
able for research purposes and in many 
processes in steel, pottery, glass and other 
works. It has been developed by an Eng- 
lish concern. 

The instrument may be regarded as a 
photometer, in which, by simply rotating 
the eyepiece, a beam of selected monochro- 
matic light from the hot body is adjusted to 
equal intensity with a beam of similar light 
from an incandescent electric lamp. It is 
not a color-matching instrument, and in 
consequence of the simple construction, ac- 
curate readings can be taken repeatedly by 
different observers with remarkable con- 
sistency. The formula, which expresses 
the relationship between the intensity of the 
radiation of a hot body and its temperature, 
has been examined both theoretically and 
practically by many investigators and has 
been shown to give results of great accu- 
racy up to the highest temperatures. The 
constants of this formula for every instru- 
ment are individually determined at several 
temperatures before calibration. 

The general arrangement of the instru- 
ment is shown in the figure and includes : — 
The pyrometer, consisting of the optical 
system, the electric lamp, the shield carry- 
ing the temperature scale and pointer ; the 
teak carrying-case with fittings for fixing 
the pyrometer and standard lamp for check- 
ing; 4-volt accumulator, ammeter and reg- 
ulating resistance, complete in teak case; 
the standard lamp and an adjustable tripod 
stand. 

The following is a brief explanation of 
the construction. Behind the enlarged part 
in the front of the pyrometer in which is 
fitted the electric lamp, are two holes. 
Light from the object (such as a furnace) 
under observation passes thru one, and 
light from the lamp thru the other. These 
beams of light then pass thru a system of 
lenses and prisms, are polarised in differ- 
ent planes and rendered monochromatic. 
Finally the two beams of light pass thru 
a single ocular. The observer sees an il- 
luminated circular field divided into two 
semi-circles One semi-circle is filled by an 
image of the hot body under observation, 
while the other is uniformly illuminated by 
the electric lamp. The two semi-circles are 
brought to an equal intensity of illumina- 
tion by turning the eyepiece to which the 



scale pointer is directly attached as seen. 

In this manner the unknown rays are 
compared with those of known intensity 
from the electric lamp. As the accuracy 
depends upon the constancy of the light 
from the electric lamp, a small ammeter 
and regulating resistance are fitted in the 




box containing the accumulator to ensure 
that whatever the voltage of the battery 
may be, the current passing thru the lamp 
is constant. To ensure that the candle- 
power of the lamp shall remain constant 
over long periods as the filament ages, pro- 
vision is made for calibrating the instru- 
ment from time to time against a stand- 
ard amyl-acetate lamp, and thus ascertain- 
ing the correct reading of the ammeter, 
when the electric lamp is giving the cor- 
rect illumination. This test need only be 
made at long intervals and the standard 
lamp need not be carried into the factory 
or plant. 

The pyrometer is supplied fitted with one 
or more temperature scales of any desired 
range from 700° C. upwards, but the fol- 
lowing standard ranges are suggested as 
suitable for most practical considerations: 
single scale instruments, 700-1400°C. ; sin- 
gle scale instruments, 900-2000°C. ; double 
scale instruments, 70O-14O0°C. and 1200- 
2500°C. ; double scale instruments, 900- 
2000°C. and 140O-4000°C. 



ELECTRIC COUCH INDUCES 
CURRENTS IN THE BODY. 

By H. H. Parker 

The electric couch described in this ar- 
ticle makes possible a simple application of 
the commercial alternating current in the 
electro-therapeutical treatment of insomnia, 
hardening of the arteries, nervous dis- 
orders and other similar ailments ; a num- 
ber of sufferers from such troubles claim 
that they have been greatly benefited thru 
its use. While the apparatus has been con- 
structed in various forms, the one described 
has the advantages of simplicity, lightness, 
neat appearance and ease of operation, pro- 
vision being made for connection to any 
lighting circuit carrying alternating current 
at 110 or 220 volts and any frequency. 

The couch itself is an ordinary wicker- 
work affair, to the bottom of which are 
fastened a series of coils, wound upon lam- 
inated sheet iron cores. In the one shown 
in the illustration eight coils are used, con- 
nected in series for 220 volts and in series- 
parallel in groups of four in series when 
operating on 110 volts. At a convenient 
point at the head of the couch is placed a 
wall key socket for cord and plug. 

Owing to the use of alternating current, 



laminated i on cores must be provided for 
the coils; these are built up of No. 22 gage 
iron strips one and a half inches wide by 
twenty-six inches long, the completed core 
being about half an inch thick. The strips 
are shellacked before being put together, 
and are held by paper insulated rivets in 
order to prevent the formation of eddy 
currents in the iron or rivets. After in- 
sulating the cores they are wound with 
two layers each of No. 20 D.C.C. magnet 
wire, coated with shellac or insulating var- 
nish, wrapt with cotton armature binding 
tape and then bent to conform somewhat 
to the curve of the couch surface when 
sagged by the weight of a patient lying 
upon it 

As part of the equipment a Test Coil is 
provided. This comprises a built-up iron 
core similar to the others, but only about 
three-quarters of an inch square in section. 
At its center is wound two layers of No. 
25 D.C.C. magnet wire in a coil about six 
inches long, the terminals of which are 
carried to a miniature lamp socket at the 
end of the core containirjg a two-and-a-half 
volt battery lamp. This wand-like con- 
trivance is considered by the patient an in- 
dispensable part of the outfit, and is used 
to determine when the couch is "working.'' 
When brought into the influence of the 
rapidly alternating, magnetic field surround- 
ing the coils the little lamp is lighted, the 
dimensions of its coil being such that the 
core may be laid upon the couch in close 
proximity to the coils beneath without 
danger of burning out the bulb. By moving 
the test coil away from and around the 
couch a visible demonstration of the strength 
and extent of the magnetic field is af- 
forded. 

To operate the couch the patient merely 
lies down upon it and switches on the cur- 
rent. No physical effect is noticeable be- 
yond a slight vibration due to the alter- 
nating current, the beneficial results ob- 
tained being supposedly an effect of the 
rapidly alternating magnetic field surround- 
ing the body. 

There appears to be a difference of 
opinion among medical men as to the exact 
action of this magnetic field upon the hu- 
man system, but in looking at the subject 
from the engineer's instead of the physi- 
cian's viewpoint, the following theory sug- 
gests itself : Do the blood circulatory pas- 
sages, the veins and arteries, or any of the 




Unique Electric Couch Which Passes Power- 
ful, Alternating Magnetic Fields Thru the 
Body. 



organs or other parts, form, as it were, 
the closed secondary circuit of a trans- 
former, in which currents are induced 
through the action of the magnetic field 
produced by the alternating current flowing 
in the primary winding of the coils beneath 
the couch? 




June, 1917 THE ELECTRICAL EXPERIMENTER 99 



Prof. Bell Receives "Civic Forum Medal" For 1917 



SIR OLIVER JOSEPH LODGE. 
June, 1917, Marks His 66th Birth 
Anniversary. 

One of the most profound scientific 
workers and thinkers we have ever had, is 
Sir Oliver Joseph Lodge, who is still an 
active figure in the field of scientific re- 
search, and all of us expect in the near 
future to see something even more won- 
derful than any of his preceding discoveries 
and inventions. 

•Sir Oliver Joseph Lodge was born on 
June 12, 1851, at Penkull, Staffordshire, 
England. He received his early education 
in the Newport Grammar School and later 
he entered the University of Coll, London, 
where he specialized in scientific and mathe- 
matical research. His scientific trend was 
noticed by the professors of different uni- 
versities, and after he had graduated from 
this institution he was elected as Profes- 
sor of Physics at the University of Liver- 
pool. Since 1900 he has been principal of 
the University of Birmingham. 

He has had many honors and degrees 
conferred upon him and is an active mem- 
ber of many of the leading scientific in- 
stitutions. Sir Oliver Lodge was presented 
with the honorary degree of Doctor of 
Science from Oxford, Cambridge, Victoria, 
Liverpool and others, also that of LL.D. 
from St. Andrews, Glasgow and Aberlaide. 
He was president of the Mathematical and 
Physical section of the British Association 
in 1891 and President of the Physical So- 
ciety of London. His most important work 
in electro-physical science is that of wire- 
less telegraphy, in which he has introduced 
some of the most fundamental steps in 
commercializing this fascinating art, and 
in fact he is called by many the father of 
wireless. The Lodge coherer was the first 
instrument used for successfully receiving 
radio waves. 

He discovered in 1889 that two metal- 
lic surfaces in perfect, but not conducting 




Sir Oliver Joseph Lodge, Famous Eng- 
lish Physicist and Savant. He Is Re- 
garded by Many as the Dean of Pres- 
ent-Day Scientists. 



contact, were welded together when an elec- 
tric discharge past between them, and later 
on studied the propagation of electric waves 



The accompanying photo shows the pre- 
sentation of the "Civic Forum Medal" for 
1917, to Dr. Alexander Graham Bell, the 



inventor of the telephone. Those in the pic- 
ture from left to right are : John J. Carty, 
chief engineer of the American Telephone 
and Telegraph Company ; Union N. Bethell, 
president of the New York Telephone 
Company and senior vice-president of the 
American Telephone and Telegraph Com- 
pany; Dr. John H. Finley, (presenter of the 
medal) ; Alexander Graham Bell, inventor 
of the telephone, and Thomas A. Watson, 
associate of Dr. Bell, maker of the first 
telephone instrument and receiver of the 
first telephone message. On the table are 
the first instruments used by Dr. Bell. 

On March 21, in Carnegie Hall, New 
York, Dr. Alexander Graham Bell, was for- 
mally presented with the Civic Forum 
Medal of honor for distinguished public 



along wires. He thus came into close 
contact with the researches of Hertz on 
the creation of electromagnetic waves in 
free space, and this work he both expounded 
and extended. 

His interest in these matters was, how- 
ever, scientific rather than technical, and 
he himself has admitted that before the 
matter had received attention from others 
it had not occurred to him to suggest 
the employment of Hertzian waves for 
practical telegraphic purposes. In the 
course of his scientific work he had di- 
rected much attention to the phenomena 
of electrical resonance. Hence, when it 
had been indicated that the chief prac- 
tical importance of Hertzian waves might 
be in their application to space-telegraphy, 
Lodge was not slow to apply his knowl- 
edge to this subject. 

On May 10, 1897, Lodge applied for a 
provision patent protection in Great Britain 
for improvements in Syntonizing Teleg- 
raphy Without Line Wires, and in this 
document he states that the subject of his 
invention was to enable an operator to 
transmit messages across space to any one 
or more of a number of different individ- 
uals in various localities, each of whom is 
provided with a suitably arranged and 
"tuned" receiver. The subject-matter of 



service, in recognition of his invention of 
the telephone in 1876. 

The medal was established in 1914 to ex- 




press the sentiment of the American people 
toward their great living men and women. 
Its purpose is to promote more general ap- 
preciation of distinguished public service 
and inspire ambition to emulate such ser- 
vice. 

The medal this year was awarded to Dr. 
Bell by vote of the members of the National 
Council of Seventy, representing the whole 
country, geographically and so far as pos- 
sible in all other respects. 

The medal was first presented to Maj. 
Gen. George Washington Goethals, U. S. 
A., in 1914 for his work in building the 
Pan ama Canal. In 1915 it was presented to 
Thomas A. Edison in recognition of his 
contributions to electrical inventions. 



the specification deals exclusively with the 
utilization of electromagnetic waves. This 
is the noted Lodge tuning patent which 
is universally employed in all forms of 
radio transmitting apparatus today. The 
patent recently expired and became public 
property. 

Sir Oliver Lodge is a noted author, and 
some of his most important works are 
"Elementary Mechanics," "Modern Views 
of Electricity," "Pioneers of Science," "Sig- 
nalling Thru Space Without Wires," "Life 
and Matter," "Lightning Conductors and 
Lightning Guards," "Modern Views of Mat- 
ter," "Man and the Universe," and his latest 
book, "Raymond — A Treatise of Life and 
Death," which purports to prove that the 
author actually received communications 
from his dead son, who was killed while 
serving with the English army in France. 
His theory however was received coldly 
by the scientific world. 



HOW ELECTRIC VEHICLES 
BOOST EFFICIENCY. 

A New York department store speeds 
up the loading of its delivery wagons by 
running its "electrics" inside of the build- 
ing and transporting them to various floors 
on large elevators. 




Copyright by Internationa! Film Service. 



The Inspiring Moment When Professor Bell, Inventor of the Telephone, Was Presented 
With the "Civic Forum Medal" at New York, on March 21st. Reading Left to Right — 
John J. Carty, Union N. Bethell, Dr. John H. Finley, Prof. Bell and Thomas A. Watson, 
Who Made the First Telephone for Prof. Bell. 



100 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



Joe's Experiment 



t< A^'D another thing," Mr. Robertson 
/\ checked Pete ; "don't bring that 
/ \ blind kid around here any more. 
He's just in the way, and if he 
gets hurt the company'll have the 
damages to pay. What business has a 
blind kid got around an electric plant, 
anyhow? You keep him out of here, 
understand ?" 

Pete Foley whirled and surveyed the 
nervous, drawn face of his chief for a 
moment, and then flung back hotly : 

"Look here, that boy's a friend of mine 
and a mighty good friend. He's not in 
your way when he comes around here, and 
I'm responsible for his safety. As for 



By C. M. Adams 

the mountain-side, Joe Benson paused and 
listened to the faint purr of unit No. 1, 
far away down the slope. Ever since the 
Snake River Power Company had started 
the first day's work on this water power 
project, Joe had been an interested listener 
of everything that went on. Listening had 
been his chief avenue of impression, for 
his eyes were useless, and had been 
so for several years. He had heard the 
rumble of the blasts, and the grit and 
grind of drills and steam shovels as they 
prepared for the big concrete dam which 
held back the water. He had listened and 
been interested, but mystified, until Pete 
Foley, a member of the electrical construe- 



as much about the plant as I do," one of 
them ejaculated admiringly, after Joe had 
come off victorious in a technical argument. 

"Sure he does," Pete retorted. "Don't 
think he don't know anything because he 
can't see. He'll make his mark — you 
watch." « 

At first the size of the Snake River- 
project had dazzled Joe. Then with a 
realization of the extent of the undertak- 
ing had come, at first as a dream, and 
then a resolve, the idea that he, too, would 
become an electrical man, an electrical en- 
gineer. True, he was blind. But he was 
attending the high school up the valley 
and in two years would be ready to enter 





"No, you don't. Not me," Pete interrupted, as Mr. Robertson turned to him. "Here's the boy you want to thank. He saved your plant 

and not me." 



what business he's got around an electric 
plant, let me tell you that he knows more 
about electricity right now than some men 
who are paid big money for what they 
are supposed to know. He'll make his 
mark some of these days when he gets 
into the electrical world, you'll see. And 
furthermore, he's going to come here when- 
ever he wants to, as long as I'm around." 

Mr. Robertson's white, haggard face 
flushed angrily and his lips parted as if to 
speak. But he was silent as Pete swung 
out of the power house and up the trail to 
the company's tool shack. Pete Foley was 
a good electrician, a very good electrician, 
and men with this particular kind of good- 
ness were so scarce in these mountains 
that it behooved Mr. Robertson to stand 
for much from this member of his con- 
struction crew. 

Half way up the road to his home on 



tion crew, had come to board at his home. 

It was Pete who had answered his hows 
and whys about the plant and its opera- 
tion, and during the year which had 
elapsed Joe absorbed electrical information 
like a dry sponge taking in water. 

At first he had listened to the conversa- 
tion of the men, but had been loath to 
take part in it because he felt his own 
ignorance of their work. However, as 
time past, and Pete's daily instructions bore 
fruit, he began to take a more active part 
in the talk of the men during the evening. 

At first they had regarded him as an 
outsider, whose ignorance of their work 
was to be tolerated for politeness sake only. 
But gradually, as Joe's comments and ques- 
tions became more intelligent, they began 
to look to him as an equal — as one of their 
own number professionally. 

"I'll be hanged if that kid don't know 



the university. Other blind men had done 
things equally as wonderful. Why could 
he not enter this field? 

And what a day this had been, what a 
wealth of impression and sensation. He 
had stood beside the great towering masses 
of iron and copper, and had felt with his 
own sensitive hands the giant castings and 
coils of the great generators, while Pete 
explained how they were built and worked. 
So this April afternoon he went home 
warmly glowing with new impressions and 
desires. 

Pete did not have time to talk after 
supper. He went upstairs for his clothes 
and then disappeared down the slope in 
the company car, on his way to Merwin 
to complete preparations for the trans- 
formers in the sub-station there. And so 
Joe sat on the porch and listened to the 
faint hum of the generators below him, 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



101 



L 



while lie dreamed of his future. 

Two days later when Pete returned from 
Merwin, Joe was waiting for him after 
supper as the group of boarders gathered 
on the porch. 

"Pete," Joe began, "I've been wanting to 
ask you something since day before yester- 
day, but you weren't here to answer it." 

"Go ahead, but don't go too deep. Re- 
member I'm only an ordinary electrician," 
Pete warned. 

"Well," Joe went on, 
"on one of those switch- ^^^^^^^ 
board panels you showed 
me the other day there 
was a rheostat, but you 
didn't say what it was 
for. What does it do, 
anyhow?" 

"Oh, that's the rheostat 
for the exciter's field," 
Pete responded. "It's 
connected in the shunt 
winding of the exciter 
field coils. It controls 
the voltage." 

"What does it do that 
for?" Joe insisted, going 
to the bottom of the mat- 
ter. 

"Well, here's the idea," Pete explained. 
"You see the exciter supplies current to the 
field of the big alternator. Well, the volt- 
age of the alternator will depend on the 
voltage of the exciter, because if the volt- 
age of the exciter changes the strength of 
the field will change and affect the alter- 
nator's voltage. So if they want to raise 
or lower the voltage of the big alternator, 
they just raise or lower the exciter volt- 
age by putting in more or less resistance 
with this rheostat. Do you understand?" 

"Oh, yes." Joe replied. "Then by ad- 
justing this field rheostat on the exciter 
you can change the voltage of the big 
alternator." 

"Exactly." Pete assented. 

Joe sat for some moments, thinking of 
this new addition to his store of electrical 
information, while the men about him 
talked lazily. 

"Robertson's getting grouchy about those 
transformers. I tell you," one of the men 
said a moment later. 

"If they don't come, the company won't 
be able to get its franchise, and he seems 
to think it's up to him to get them here." 

"I know that all right, but he oughtn't 
to treat the rest of us like we were to 
blame," Pete retorted. "He's been a fright 
for the last two weeks." 

"What transformers are those?" Joe 
asked. 

"The transformers for the Merwin sub- 
station, the step-down set," Pete informed 
him. 

"Haven't they come yet?" Joe asked in 
surprise. 

"No, they've been shipt a week but can't 
be located on the road or anywhere else." 

"What will he do if they don't come?" 
Joe asked in concern. 

"I don't know. That's what's bothering 
him, I guess," Pete replied. 

The generators at Portage Falls devel- 
oped current at low voltage which was 
then past thru a set of transformers which 
stept it up to sixteen thousand, five hun- 
dred volts, at which tension it was trans- 
mitted to Merwin, fifteen miles away over 
the mountains. There it was stept down to 
two thousand, three hundred volts for dis- 
tribution thru the service lines of the city. 
Joe knew this as well as the rest of the 
men. He also knew now that if the step- 
down transformers did not arrive, the 
Snake River Power Company would be in 
a very awkward position. 

Its franchise required it to supply cur- 
rent to Merwin on May first. Today was 
April twenty-seventh. 



Joe knew that the sixteen thousand volt 
current could not be turned directly into 
the city lines. He knew that burned out 
equipment and electrocuted people would 
be the result. The voltage had to be low- 
ered, but how? He wondered about it and 
tried to think what Mr. Robertson would 
do, as he sat on the porch and listened 
to the men talking, and far away the faint 
hum of the generators in the power house, 
limbering up their bearings.- 



AST month we publisht a rattling good story — "Eddy Currents" — 
by Mr. Adams. We confidently believe that the present tale will 
appeal to all dyed-in-the-wool electrical readers. You don't require an 
electrical education to become "en rapport" with the author, as he pos- 
sesses that happy faculty of weaving the technical and personal aspects 
in such a way that the moral cannot be mist. The facts related in this 
story are human, pertinent every-day affairs. Similar obstacles to those 
facing invincible Joe Benson, the hero of this narrative, have confronted 
all of us at one time or another. But true "Philosophy" will unlock all 
doors and surmount the greatest of barriers. 



Of what use would this power be if 
there were no transformers at Merwin? 
Without the intervening coils the big ma- 
chines would be as useless as if their wind- 
ings were stript from them. He thought 
of this and tried to answer for himself the 
question that was puzzling the chief of 
construction. 

"What do you suppose Mr. Robertson 
will do?" he asked Pete as the latter started 
upstairs for bed. 



IN THAT "JULY" E. E. 

Arc There Currents About a Mag- 
net? — with a -number of original pho- 
tos and charts never publisht before. 
— by F. F. Mace. 

"Cold Light" or La Lumiere Froide, 
as the French call it. The work of 
Prof. Dussaud. 

Back to the Days of "V olta"—n.vith 
some extremely interesting photos of 
Volta's original apparatus — by Jacques 
Boyer, our Paris Correspondent. 

"Ham Jones — Scientist" — a rollick- 
ing good electrical story with a live- 
wire wallop in every line by H. IV. 
Eveleth. 

The Marvels of Radioactivity by 
Jerome S. Marcus. 

Lightning — How to Protect Your- 
self from It — An article everyone 
should read by W. G. Whitman. 
With illustrations. 

Where the Radio Amateur Fits in 
the U. S. Naval Reserve Force by 
M. B. West. 

A Page of Marvelous X-Ray Skia- 
graphs, including one of a four- 
legged chicken. 

The Calculation and Measurement 
of Inductance — Conclusion by H. 
Winficld Secor and Samuel Cohen. 

Besides these and a large num- 
ber of other valuable and interesting 
articles, there ivill appear a liberal 
sprinkling of timely summer-time 
topics of interest to all readers. Don't 
miss the "July Issue!" It'll be right 
there waiting for you with a zvallop 
on every page. 



"Go crazy, if those transformers don't 
come," Pete replied unconcernedly. 

The next day Joe found himself think- 
ing of the problem again as he heard the 
machines purring away on his way home 



from school. That night as he sat on the 
porch he was still thinking of it, and yet 
had found no ready solution for the dif- 
ficulty. 

"I don't see how they're going to fix 
that up if those transformers don't come," 
he complained to Pete. 

"Great guns, you aren't trying to figure 
out a way, are you?" Pete exclaimed. 

"Why yes, I ought to be - able to, or try 
anyhow," Joe protested. 

"Let Robertson do that. 
^^^^^^^ He's paid for worrying," 
Pete returned easily. 

But that did not satisfy 
Joe. The plant below 
him had grown under his 
very doorstep. He had 
heard every bit of metal 
and concrete put into 
place, and he felt as if 
the thing were his own. 
Then, too, was he not go- 
ing to be a consulting en- 
gineer some day ; would 
not a problem similar to 
this be put to him for 
solution ? He ought at 
least to attempt to solve 
it now. So he puzzled 
his brain over the thing that night and 
all the next day, suggesting, rejecting, 
scheming and pondering. But by the eve- 
ning of the twenty-ninth he had not 
reached any solution. 

He was not the only one who was think- 
ing of this problem. The worried, anxious 
face of Mr. Robertson, with its black- 
ringed eyes, glittering with sleeplessness, 
testified too plainly of his own struggle 
over the proposition. 

He remained at Portage Falls directing 
bits of finishing work, while he hoped and 
almost prayed for the momentary arrival 
of the coils so much needed. Hourly he 
telephoned to Merwin to see if they had 
arrived. Hourly he hoped that they might 
have come, and then grew despairing as he 
was told they had not. 

On the morning of the thirtieth he went 
to Merwin with the determination of stay- 
ing there until they came, and hoping 
against hope that service could be started 
on time. 

Pete and the others stayed behind at 
Portage Falls, finishing up fine points of 
the work there. The plant was in order, 
each great machine ready to send its thou- 
sands of kilowatts over the line to Merwin 
to be used for every sort of work, pro- 
vided the intervening transformers were 
there to step down the deadly high tension 
to a safe voltage. But at noon a message 
to the Falls reported that no transformers 
bad arrived. 

Pete loafed up the steps of the Benson 
home at dinner time. Worry over what 
would happen to the company did not in- 
terfere with his appetite, and he was ready 
for the food awaiting him. 

But five minutes after he had sauntered 
leisurely inside, he dashed out, leaped off 
the porch, and raced down the steep hill- 
side, recklessly speeding toward the com- 
pany's tool shack at the bottom. A minute 
later he flung open the doors of the build- 
ing and was cranking the little service 
automobile. Two minutes later and the 
pebbles were flying in a stream from his 
tires as he bumped away over the rough 
roads toward Merwin 

An hour and a half later he stopt Mr. 
Robertson's big high-power roadster before 
the building, while the chief himself sprang 
out and dashed down to the power house, 
with Pete closely pursuing him. 

* * * * * * 

It was a varied group which clustered 
about the switchboard, handsomely drest 
directors, oilers and workmen in overalls, 
(Continued on page 150) 



102 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



AN ELECTRIC SEMAPHORE FOR 
AUTOISTS. 

The accompanying photograph shows a 
cleverly designed automobile electric sig- 
nal device which has recently been devel- 
oped by the well-known civil engineer, Mr. 
H. Hartman, of New York City. 



Ll 



hands or not, as becomes readily apparent. 

The Instructograph consists of three 
units : the transmitting unit, the receiving 
unit and a battery case, and while the pieces 
are of light and compact construction, the 
complete installation weighing but six 
pounds, without batteries, they have been 
designed for the strength and durability 
necessary for the hard usage they will be 
subjected to in service. 

The Transmitter consists of a 
case, of light metal construc- 
tion, about six inches long, three 
inches thick, and an inch wide. 
A series of six double throw 
keys project from one edge, to 
the right and left of which ex- 
Motorists Will Be Interested In the te r nd engraved plates, bearing all 
Electric Semaphore Signal Here lllus- ot the instructions commonly 
trated. It Is Operated By Electro- usec l ; n teaching the art of flying. 
Magnets, Controlled By a Push Button T , , ^uS-h or* nf e,,r-1 n 

On the Steering Wheel. The Arm llle ke y s . Which are Ot such 
Hangs Downward Normally, and Car- size that they can be easily 
ries a Red Signal Lamp At Its Ex.- bundled with gloved hands, can 

be thrown to either the right or 
left, remaining in the position 
placed until released by a touch, when they 
fly up to their normal vertical position. The 
twelve instructions themselves, neatly let- 
tered, have been chosen with great ingenu- 
ity and are so placed that actual air work 
cannot necessitate the use of both of the 
two directions, placed by each of the keys, 
at the same time. The case itself can either 
be fastened bv the side of the instructor, or 




tremity. 



The Bull's-eye At the 
Is Also Illuminated. 



This, like other inventions of Mr. Hart- 
man, is really quite simple in construction 
and performs its functional duty just as 
well, or perhaps better, than many existing 
and more complicated similar devices. The 
sole purpose of this instrument is to warn 
an automobilist in which direction the ma- 
chine ahead of him is going to turn, either 
to right or left. 

It consists of a mag- 

netic field having two 
magnetizing coils similar 
in design to the field of a 
motor. An armature coil 
is placed in this field, and 
its shaft is attached to the 
signal or semaphore arm. 
The field and armature 
are enclosed in a water- 
proof metal case which is 
seen on the left. One end 
of the pointer is fitted 
with a red lamp so as to 
serve as a danger signal. 

The armature and field 
coils are connected to a 
storage battery and a sim- 
ple switch, so that the au- 
toist can throw the arm 
either towards the left or 
right, whichever the .case 
might be. The principle 
upon which this instrument is based is that 
of the repulsion and attraction of two dif- 
ferent magnets, one stationary (the field), 
while the movable magnet is the armature. 
The arm at its normal position points 
downward, and as soon as the proper cur- 
rent is past thru the field and armature, 
the pivoted arm turns instantaneously to 
that direction, by virtue of the attraction 
between a field coil and the armature coil. 
Automobilists of to-day whose slogan is 
Safety First will appreciate this very valu- 
able device, as it cannot be mistaken owing 
to the relatively large moving surface called 
into play. 

AN ELECTRIC INSTRUCTOGRAPH 
FOR TEACHING AVIATORS. 

One of the latest Sperry devices for avi- 
ators, or rather for would-be aviators, -is 
known as the Instructograph and is illus- 
trated herewith. It is intended to facili- 
tate the instruction of pupils in the modern 
two-passenger tractor aeroplane. Prior to 
the advent of this clever device the Pilot- 
Instructor, occupying the rear seat of the 
machine, depended on twitching the various 
controls, after attracting the attention of his 
pupil-passenger by kicking the back of the 
forward seat, for imparting such instruc- 
tion as was necessary. This crude method 
of communication is very dangerous, as at 
times neither pupil nor instructor know 
whether the control of the plane is in their 




The Electrically Operated "Instructograph" Enables the Tea 
Up the Proper Signals Instantly Before the Pupil- Passenger; 

Superior to Twitching the Various Controls. 



set into the instrument board before him, 
as found convenient. 

The Receiver is a box approximately sev- 
en inches long, five inches wide and slightly 
over one inch thick, adapted to fasten on 
the wheel of the front control itself in the 
front cockpit of a tractor, under the cowl, 
or in the instrument board. Its cover is 
perforated by twelve oblong windows, 
closed by translucent white celluloid, with 
no lettering of any kind visible to confuse 
the pupil. When one of the keys of the 
Transmitter is thrown, the corresponding 
direction appears on a window in dense 
black against an illuminated white back- 
ground. Three of the directions : "Nose 
Down," "Over Banking" and "Over Con- 
trolling" flash out in black against a red 
background, clearly indicating the urgency 
of the command. An ingenious arrange- 
ment of small electric light bulbs enables 
this method of communication to possess 
the advantage of positively attracting the 
pupil's attention whenever a word of in- 
struction is given, it having been found ex- 
perimentally that the flash of light accom- 
panying the change of direction catches his 
subconscious attention. To safeguard 
against the possibility of a burned out bulb 
preventing the direction from being re- 
ceived, the circuits are so arranged that a 
second lamp remains lighted. 



NEW METHOD OF MEASURING 
FRESSURE OF LIGHT. 

In a paper to the Physical Society, Mr. 
Gilbert D. West describes the measurement 
of the pressure of light by a method re- 
quiring few of the elaborate precautions 
generally necessary in such experiments. 
The essential feature of the apparatus was 
a strip of gold leaf suspended in the mid- 
dle of a test tube containing air or hydro- 
gen at reduced pressure. Radiation from 
a 32 c.p. carbon filament lamp, impinging 
directly on one side of the strip, was suf- 
ficient to cause a microscopically measure- 
able deflection of the end. 

The pressure of normally incident radi- 
ation on a perfectly reflecting surface has 
been shown by Maxwell and others to be 
numerically equal to twice the energy con- 
tent of the radiation per unit volume, and 
hence, if this quantity be measured in the 
way described below, a check on the orig- 
inal observations can be made. A mean 
of the results of several successive experi- 
ments with the deflected strips gave a value 
for the pressure of radiation which only 
differed from that calculated from the en- 
ergy density by a small percentage. The 
accuracy and constancy of the final results 
seemed to preclude their being seriously 
affected by gas action; but, as gas action 
had to be taken into consideration, the pres- 
ent research was undertaken with a view to 
its fuller investigation, and if possible to 
complete elimination. 

In measuring the energy 
density, the initial rate of 
rise of temperature of a 
blackened copper plate, 
enclosed in the tube, was 
measured by means of an 
attached copper eureka 
thermo-junction. Due al- 
lowance was made for 
cooling corrections, and 
the lamp black was as- 
sumed to absorb 95 per 
cent of the incident radi- 
ation. The cold junction 
was immersed in oil con- 
tained in a vacuum flask, 
and during an experiment 
a delicate indicating ther- 
mometer in the oil only 
showed negligible varia- 
tions. The calibration of 
the thermo-junction was 
carried out in the usual way, and a num- 
ber of minor matters received full con- 
sideration. 

When from the measurements thus taken 
the energy reaching 1 sq. cm. in one second 




cher to Flash 
which Is Far 




Arrangement of Apparatus for Measuring 
Pressure of Light. — H is Hollow Stopper, E 
Is Cover Glass Cemented to Tube. F Con- 
tains Pith Charcoal, G Is Tube Which May 
Be Connected to Gaide Pump. 

is known, the energy per 1 c.c. can be cal- 
culated from a knowledge of the velocity 
of light. 

(Continued on page 142) 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



103 



NEW TELEPHONE SIGNAL A 
PATIENCE SAVER. 

Patience vanishes rapidly while holding 
a telephone line. Save your time and at- 
tend to other important matters while wait- 
ing for the other party to resume conver- 
sation, say the sponsors of the new Hold- 
the-call-signal here illustrated. This clever 




tries to drum 



How Often Do You Feel Like Cussing the 
Telephone When Party No. 2 Says "Hold the 
Line"? The Answer Is — Don't. Place the 
Receiver On the Amplifier Here Shown and 
You Will Hear the Party Answer. 

device will let you know when the speaker 
is ready. No electrical connection is needed. 
It simply rests alongside of the instrument 
and the receiver is placed on it while line 
is held open. 

HOW STUDENTS STUDY WAVE 
MOTION. 

When the college "Prof.' 
the principles of wave mo- 
tion into his pupils' crani- 
ums, he has available to- 
day the mechanical wave 
reproduction machine here 
illustrated. The small white 
discs form into various 
lines representing curves or 
waves of certain kinds, de- 
pending on how the appa- 
ratus is operated. This re- 
markable model was in- 
vented by Dr. Charles 
Forbes of Columbia Uni- 
versity. With this appara- 
tus the formation and 
propagation of the three 
general classes of wave 
motions may be demon- 
strated, namely : 

Water or Surface Waves, 
in which the elliptical mo- 
tion of the particles of 
water, the advancing of 
the crest tending to form 
breakers, the recession of 
the trough tending to form 
the undertow are exhibited. 
Sound Waves, or waves of condensation 
and rarefaction, in which the amplitude 
of vibration may be changed by lowering 
the disc support. The lowering of the 
distant end of the support will also repre- 
sent the decrease in the loudness of sound. 
Ether Waves, or transverse vibrations, rep- 



UNIQUE ELECTRIC SOLDERING 
TOOL. 

A Buffalo concern has 1 ^ntly brought 
out a new form of electric soldering tool. 
Among these tools is a two-prong iron with 
prongs of solid bar brass with nickel- 
plated finish. This type of iron is furnished 
in capacities of 150 watts, 250 watts and 
500 watts. All are designed to work on 
low pressure, from 6 to 15 volts, either di- 
rect or alternating. This pressure can be 
obtained from an ordinary lighting or 
power circuit, either 25 or 60 cycles by in- 
terposing a low-voltage transformer, or a 
storage battery operating at a pressure of 
12 volts can be used. Under no circum- 
stances may these irons be used on any 
voltage over 15. 

Another type is the two-handle portable 
soldering outfit. This is composed of a 
single prong soldering tool attached to one 
wire of the secondary side of the trans- 
former and a solder-feeding tool attached 
to the other secondary wire of the trans- 
former. When a storage battery is used 
the single prong soldering tool is attached 
to the negative side, and the solder-feeding 
tool to the positive side of the latter. 

When soldering with this outfit the sin- 
gle prong point is brought to bear upon 
the object to be soldered, and the solder- 
feeding tool is brought to bear upon the 
spot where soldering is needed. The in- 
stant the circuit is closed the heat point 
glows with a white heat, and the solder is 
held until the work is done. The current 



AN AUTOMATIC EXTENSION 
REEL FOR DROP LIGHTS. 

The automatic extension reel here illus- 
trated is intended for drop or portable elec- 
tric lamps. It is simple in construction and 
positive in operation. 





Several Styles 
Voltage A.C. < 




By Means of This Oscillating Pendulum 
Cabinet It Becomes a Sinecure for the "Prof.'' 
to Inculcate His Pupils with the Funda- 
mentals of Various Wave Motions. 



resenting the production of light, heat and 
electric waves. The progressive undula- 
tions of a vibrating cord are also repre- 



of a Unique Electric Soldering Iron That Operates On Low 
r D.C. Closing the Circuit Causes the Points to Heat Up, 
When the Solder Is Applied. 

ceases to flow as soon as the heating point 
is taken from the work. This outfit is 
made in 150- and 300-watt capacities and 
is designed for use on direct or alternat- 
ing currents up to 12 volts pressure. 



sented. Comparison of Phases. The ap- 
paratus admits of a ready comparison of 
similar phases in the three systems of wave 
motions, a very desirable feature not pos- 
sest by any other form of wave machine. 
By means of the covers resting upon the 
framework of the apparatus any one or two 
of the wave systems may be hidden from 
view, thus leaving the remainder for spe- 
cial examination when desired. The front 
of the apparatus exhibits the conversion of 
rotary into direct and lateral reciprocating 
rectilinear motions. On the back, the ac- 
tion of the crank handle, the rod connect- 
ing the individual cranks, and the opera- 
tion of the double parallel rule mechani- 
cal motion, first used in this apparatus, are 
clearly exhibited. Tts large size is espe- 
cially advantageous, since the wave forms 
can be clearly seen across a large lecture 
room. 



A Clever Invention in the Form of An Auto- 
matic Extension Reel for Portable Electric 
Lamps, Which Winds the 30-foot Cord Up 
and Swivels in Any Direction. 

It is designed especially for garages, 
blacksmiths, factories, stores, or any busi- 
ness requiring an extension light. This 
reel is equipt with 30 feet of lamp cord, 
easily secured by fastening the arms of the 
swivel joint to ceiling or beam, as shown. 

This swivel joint enables one to walk in 
any direction with the lamp. It has an 
automatic lock ingeniously 
arranged to lock and hold 
the lamp any distance from 
the reel. A slight pull for- 
ward unlocks the ratchet 
and the reel revolves, wind- 
ing the cord back as you 
advance toward the reel 
with lamp in hand. 

A HANDY ELECTRIC 
DRINK MIXER. 

The soda clerk used to 
cuss (inwardly) merrily 
whenever a patron called 
for a drink that required a 
fancy mixture — a chocolate 
milk shake for instance. 
Wherefore and hence we 
have in our midst the elec- 
tric drink mixer that never 
tires — no matter if you had 
a thirst like an Arabian 
camel. 

The electric drink mixer 
is mounted on a swinging 
bracket. When the machine 
is pushed back and removed 
from the glass it takes the position indi- 
cated by the dotted lines. Throwing back 




When You Ask for a Fancy Drink at the 
Soda Fountain the Dispenser Now Places the 
Glass Under An Electric Drink Mixer. 

the bracket operates a switch which breaks 
the circuit. The swinging down of the 
bracket automatically closes the circuit. 



104 THE ELECTRICAL EXPERIMENTER June, 1917 



Electricity and Life 

The Uses of High-Frequency Currents in Medical and Lecture Work 
By FREDERICK FINCH STRONG, M. D. 
Lecturer on Electro-therapeutics, Tufts Medical School, Boston 



T 



Senses 



(Third Article) 

HE phenomena of high-frequency 
currents offer us a fascinating held 
from which to select experiments for 
public lecture demonstration. In his 
lectures on "The Realms Beyond the 
the author has used high-fre- 



ductance coil being adjusted to balance the 
different capacities added to the resonator 
terminal. 

This little resonator is made by winding 
600 turns of No. 30 triple cotton covered 
wire upon a shellacked paper cone, 12 
inches in diameter at the bottom, 5 inches 




Hardening of the Arteries — Most Dreaded of Ailments in Later Life — Is Successfully Treated 
By Placing the Patient Within a Wire Cage, Thru Which High-frequency Currents Surge at a 
Frequency of 600,000 Cycles Per Second: D'Arsonval's Method. 



at the top, and 14 inches high. It is a 
difficult matter to insulate this small coil 
as the turns of the winding are very close 
together ; it can be done, however, by the 
use of from six to eight coats of Armalac. 
The primary coil is a ring, 18 inches in 
diameter, formed of five concentric turns 
of thin copper ribbon 1 inch wide. The 
exciting apparatus is the same as that de- 
scribed in the last paper in connection with 
the large resonator, except that a Yz K.W. 
transformer is used instead of the heavy 
1 K.W. (See Fig. 2.) 

The writer also employs a standard 
Clapp-Eastham K.W. Tesla coil excited 
by the same apparatus (see Fig. 3). Con- 
nected with two parallel upright wires the 
spark from this coil will run up and re- 
peatedly reform again at the bottom, 
producing a very spectacular effect (Fig. 
4). 

Another brilliant experiment can be per- 
formed with two large glass flasks (ordi- 
nary carafes or water-bottles will do). 
One is filled with water containing a few 
drops of fluorescein solution — (a coal tar 
dye) — the other with water to which a small 
amount of bi-sulfate of quinine has been 
added ; the bottles or flasks are placed 
about six inches apart and a wire from the 
Tesla coil terminal inserted into the solu- 
tion in each. The current passes down 
thru the water and the arc takes place be- 
tween the glass walls of the two flasks. 
The ultra-violet rays from the discharge 
cause the water in the flasks to become 
luminous — the quinine solution with a pale 
blue light, the fluorescein with a beautiful 
apple-green. The discharge apparently 
passes directly thru the glass walls of the 
flask; in reality, of course, the current 
passes by induction rather than conduction, 
the flasks acting as condensers in series. 
(See Fig. 5.) 



quency phenomena to demonstrate the ex- 
istence of force and matter beyond the 
range of human perception. In "The Sci- 
ence of the New Age" he has employed 
similar means in calling attention to the 
fact that the investigators of to-day are 
leaving the crude matter of earth and are 
dealing more and more with Etheric Force 
— and with matter of a super-gaseous 
nature. The scientist of the future will 
have to provide himself with instruments 
far more delicate than anything hitherto 
dreamed of or else he will develop super- 
normal powers of perception by the mani- 
festation of faculties already latent in the 
human organism. 

For the traveling lecturer who wishes to 
employ high-frequency currents in his 
work, the large resonator described in the 
last issue of The Electrical Experi- 
menter may prove somewhat cumbrous and 
difficult of transportation. Those who wish 
a lighter, more compact apparatus may use 
the small resonator shown in Fig. 1. 

It is quite small, yet it sends out stream- 
ers two feet in length, and may be operated 
by a 1 2 K.W. "wireless" (step-up) trans- 
former. With this little apparatus beauti- 
ful luminous effects may be obtained — as, 
for example, by connecting the terminals 
with a tin-foil star glued to a sheet of 
glass; with a suspended umbrella (opened) ; 
with a long wire running out over the 
lecture hall, etc. 

For each of these experiments different 
tuning will be necessarv — the series in- 




The "Effleuve" or High-frequency Brush (or Spray) Treatment Has Proven 
cacious In the Treatment of Nervousness (Nerve and Brain Exhaustion) — "N 
American Electro-therapeutists Find It Very Valuable. 



from Jacques Boyer 

Highly Effi- 
eurasthenia." 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



105 



The Use of High-Frequency Currents in the 
Treatment of Disease. 

High-frequency currents are employed by 
physicians in four principal ways, each 
adapted to the treatment of 
certain types of diseased con- 
ditions. These are : 

1. "Tesla" treatment with 
■vacuum electrodes ("Violet- 
ray treatment"). 

2. "EfHeuve" or high-fre- 
quency spray. 

3. "D'Arsonval auto- 
condensation." 

4. "Diathermic" 

1. The method most fre- 
quently employed applies the 
Tesla current thru glass 
(vacuum) electrodes for the 
relief of local pain or inflam- 
mation. The little muscular 
pumps around the veins — the 
"vaso-motor system," which 
keep the blood circulating by 
withdrawing it from the capil- 
laries and sending it back to 
the heart — act more vigorously 
in tissues over which the 
vacuum 1 electrode is applied. 
In this manner waste products 
which cause rheumatism and 
gout are dissolved and washed 
away and fresh blood and white 
corpuscles are brought to in- 
fected parts, thus aiding nature 
in destroying disease-producing 
germs and their poisonous 
products. 

In most of the smaller high- 
frequency machines for phy- 
sicians' use, but one Tesla 
terminal is provided ; a coil of 
the resonator type being con- 
nected to the glass electrode 
by a flexible wire. The effects 
are largely local, but the meth- 
od is of value in relieving pain, 
swelling and congestion. The 
writer has always advocated 
the bipolar method, even for 
treating purely local conditions. 
The best results will be ob- 
tained from the use of a Tesla 
outfit of the type described 
in last month's Electrical 
Experimenter. The patient is 
to be connected to one terminal of 
the Tesla coil by means of a metal electrode 
held in both hands ( a piece of thin nickeled 
pipe will answer, 1 foot long and V/ 2 inches 
in diam.). In this way the current is dif- 



This method— ■•employed by the writer for By careful tuning a beautiful effect may 

years — enables us to obtain the wonderful be obtained. Close examination of this 

vitalizing effect of the high-frequency cur- discharge will show it to be literally an 

rents on the whole body simultaneously, electric "brush", formed of thousands of 





Startling Experiment With Two Glass Water 
Bottles Connected to Tesla Coil. The Spark 
Jumps Between the Glass Surfaces and 
Illuminates Solutions Within the Bottles. 



fused thru the entire body. The vacuum 
electrode, connected with the opposite Tesla 
terminal is applied to the skin over the 
affected part for from five to twenty min- 
utes, a very short spark-gap being used. 



with the local effects from the vacuum 
electrode. 

For the past few years the writer has 
been in the habit of connecting the Tesla 
coil with an Auto-condensation pad (as 
used in the "D'Arsonval" and "Diathermic" 
methods). This is formed of two plates 
of Bakelite, Ms-inch thick, hinged to fit the 
seat and back of an ordinary chair. To 
the back of each plate is cemented a sheet 
of tin or copper foil, covered with leather- 
ette. Suitable flexible conductors connect 
these metal plates with each other and 
with the Tesla terminal. This folding pad 
may be used in both "Tesla" and "D'Arson- 
val" treatment, and is quite as efficient for 
ordinary use as the cumbrous and expen- 
sive condenser chair or couch. 

2. For the "Tesla Effleuve" treatment a 
brass bell electrode is used. This can be 
made from a common brass oil can, the 
flat bottom being removed and the result- 
ing hollow hemisphere being mounted on 
an insulating handle ; the discharge occur- 
ring from the sharp edge of the brass. The 
patient is seated on the Bakelite pad, which 
is connected to the Tesla coil. The oppo- 
site terminal is attached to the brass bell 
electrode and a sufficient number of turns 
of the inductance coil are placed in series 
with the Tesla primary to give a full, 
smooth "effleuve" or purple brush dis- 
charge, when the .electrode is held from 
four to eight inches from the patient. 



distinct, delicate, purple threads. Upon 
each of these hair-like paths of light count- 
less millions of ions (electrically-active 
atoms), are being shot from the electrode 
to the patient at a speed of over 60,000 
miles per second ; the treated surface is 
therefore being submitted to a literal bom- 
bardment by countless microscopic pro- 
jectiles which are thrown out in periodic 
showers from the electrode, once for each 
cycle of the oscillating current. Two ef- 
fects are produced — one due to the pene- 
tration of the tissues by ozone-forming 
ions: the second to the rhythmic or periodic 
impact of the discharge upon the nerve 
endings in the skin and superficial tissues. 
The writer hopes ultimately to produce an 
apparatus of a frequency exactly synchro- 
nous with the rate of vibration of the 
sensory nerves; an "effleuve" from . such 
a coil would produce a harmless and effi- 
cient local anaesthesia so that operations 
could be performed without the use of 
ether or cocain. The effects obtained from 
the "effleuve" as now used are stimulating 
and vitalizing to a marked degree. The 
nerve endings of the skin may be regarded 
as sensitive antennae of a complicated ra- 
dio-system, and any intense sustained vibra- 
tion to which the apparatus is attuned will 
be transmitted by them to the receiving 
station. The effect therefore, is not merely 
superficial but systemic as well. Tuber- 
(Continucd on page 152) 



106 THE ELECTRICAL EXPERIMENTER June, 1917 

Experimental Physics 

By JOHN J. FURIA, A. B., M. A. 

Instructor in Physics and Science Master, Riverdale Country School 



HYDROSTATICS. 
LESSON FIVE. 

WATER is so plentiful, and we are 
accustomed to use so much .of it, 
that very few of us ever stop to 
think what a great part it plays 
in our daily lives. It is without 
doubt an absolutely indispensable sub- 




A Small Battery and a Couple of Test Tubes 
or Bottles, Together with Connecting Wires, 
Will Serve to Clearly Show How the Electric 
Current Decomposes Water. 



stance. We drink it — we clean ourselves 
and our belongings in it — our crops depend 
upon it — ourselves and the fruits of our 
toil are transported from one continent to 
another by means of it — practically every 
manufacturing industry makes use of it. 
Finally and most important, we swim in 
it. What would be the use of living if we 
had no Palm Beach or "the old swimming 
hole in the creek"? We naturally ask what 
is water anyhow? One could never guess 
the answer. Water is nothing more than 
the result of the combining of two gases — 
Oxygen and Hydrogen. Oxygen, we re- 
member, is the constituent of the atmo- 
sphere necessary to life. Hydrogen is the 
gas which burned with a pale blue flame 
in the lesson on "Gases." (See March and 
April issues of this journal.) The follow- 
ing experiment can be easily performed 
successfully : 

EXPERIMENT 25— (See Fig. 20) — 
C is a jar nearly full of water to which 
a few drops of sulfuric acid have been 
added. (The sulfuric acid is added to 
make the water a better conductor of elec- 
tricity. Water alone is not a good con- 
ductor of electricity, i. c, is more or less 
of an insulator, just as glass is.) D rep- 
resents lead wires from a battery of at 




Demonstration and Controlling Factors of 

the Hydrostatic "Siphon". A Simple and 

Effective Method of Emptying Tanks and 

Even Reservoirs When Occasion Requires It. 



least six dry cells in series, or from a 
storage cell or from the house current if 



it is direct current. If possible the elec- 
trodes should be of platinum. A and B 
are test tubes held in the hand after being 
inverted full of water and are placed over 
the electrodes. Immediately, and with a 
rapidity dependent upon the strength of the 
battery used, bubbles will form at the elec- 
trodes and rise to the top of the test tubes. 
These bubbles are the result of the decom- 
position of the water into its constituents. 
We notice that in one tube the bubbles 
form more rapidly and that there is always 
about twice as much gas in that test tube 
as in the other. Call that test tube "B.'' 
After the test tubes have been filled with 
the gases, raise them carefully without tip- 
ping. Insert a glowing match-stick in "A." 
It is found to burn brightly. This we re- 
member was the test for Oxygen. If a 
flame is applied to "B" a slight explosion 
results, which is the test for Hydrogen. 
Thus we see that water is composed of 
two parts Hydrogen to one part Oxygen. 

EXPERIMENT 26— (Fig. 21)— Illus- 
trating the principle of the siphon. A 
and B are vessels at different levels, A 
being higher than B. The vessels are con- 
nected by a piece of tubing ; bb 1 indicates 
the level of the top of the tubing and aa 1 
the level of the water in vessel A. d, 
indicates the level of the end of the tubing. 
If the tube is placed in position as indi- 




Two Forms of Automatic Siphon. Details 
for Constructing the One on the Right Are 
Given Herein. 



cated in the figure, and A contains water 
(or any liquid) at a level aa 1 , nothing 
happens. If, however, the tube is filled 
with water before it is placed in position, 
the water begins to flow from A down 
to B. The siphon will also act if the tube 
is placed in position, and if one sucks 
at the lower end ; for this is equivalent to 
filling the tube with water. The explana- 
tion of the action is as follows : The up- 
ward pressure in the short arm of the 
tube, is due to the atmospheric pressure 
(discust in the last two lessons). In the 
tube ab, this pressure is equal to the atmo- 
spheric pressure minus the downward pres- 
sure due to the weight of the column of 
water ab. The upward pressure of the 
tube at b 1 is the atmospheric pressure 
minus the downward pressure due to the 
weight of the column of water bM. The 
force tending to drive the liquid from A to 
B is greater than that tending to drive it 
from B to A. It is greater by the amount 
equal to the difference in the weight of 
the columns ab and bM and hence corre- 
sponds to the weight of the column aM. 
Evidently if d, were at the level aa 1 , the 
siphon would not operate; and if above 
aa 1 , it would operate in the other direction. 
If the column ab (for water) were greater 
than 32 feet the atmospheric pressure could 



not raise the water this distance, and the 
siphon would not operate. 

EXPERIMENT 27— Recently an auto- 
matic siphon has been put on the market, 
and it can be very easily constructed. Fig. 
22 shows the automatic siphon in the act 
of starting. It should be noticed that the 
tube is filled alternately with bubbles of air 
and water. This condition prevails only 




Apparatus With Which the Principle of the 
Submarine Can Be Demonstrated. The Small 
Vial 2, Can Be Made to Perform Many Won- 
derful Tricks By Pushing Down on Diafram 
1, or Squeezing Bottle 3 in "B". 



upon starting and shortly after, the water 
comes out solidly. Fig. 23, shows a home 
made automatic siphon and all those inter- 
ested should make one. 6, is a piece of 
lamp chimney about 3 inches long. 5, is 
a piece of glass tubing about *4 inch in 
diameter stuck thru a rubber stopper 2. 
4, is some more of the same kind of tubing 
past thru the stopper 3. The height h, 
should be about a foot and a half. 1, is 
a small hole drilled thru the lamp chim- 
ney 6. 5 and 4, should be about ^4 of an 
inch apart. As soon as our auto-siphon 
is placed in a liquid it begins to operate 
WITHOUT OUR FILLING IT FIRST. 
Thus we see that one made entirely of 
glass, as are the commercial ones, is very 
convenient in transferring poisonous liquids 
and acids, as we need not touch the liquid 
at all. There is nothing mysterious about 
this siphon and it is easily explained. When 
the bulb is immersed in the liquid, the 
liquid rushes in at 1 and at the lower end 
of tube 5. The liquid rushing in at 1 
tends to compress the air in chamber 6. 
The liquid rushing in at 5 streams up past 
the gap and thru 4. Hence the outgoing 
air takes with it some liquid, and, as noted 
before, we see alternately passing thru the 




Proving the "Law of Buoyancy," i. e., That 
Objects Weigh Less In Water Than In Air. 



tube bubbles of air and water. As there 
is less and less air left in 6, larger and 
larger quantities of the liquid pass with 
small bubbles of air intervening, until 
finally the air being all gone, the liquid 
(Continued on page 152) 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



107 




» RADIO LEAGUE 



^AMERICA 



H. Gcrnsback, Manager 



HONORARY MEMBERS 

CAPT. WH.G BULLARD. U S.N. NIKOLA TESL A , 
PROF REGINALD FESSENDEN. DR. LEE DE FOREST. 

W. H. Kir wan, Master of Radio Relays 



Denver Wireless Station Wins Prize Loving Cup 



TO a Denver boy goes the honor of win- 
ning the trophy cup for the best Ama- 
teur Wireless Station in the United 
States. This cup was donated by 9XE to 
the most efficient and best equipt amateur 
wireless station in the United States. 

We intended to call in a committee to 
decide upon the merits of the best amateur 
stations in the country, but station 9ZF in 
Denver was so far ahead of all other ama- 
teurs in sending, receiving, and efficiency, 
that it would have been a waste of time 
and energy to have consulted anyone at all. 

This station, 9ZF, is known to every 
progressive amateur in the United States, 
and is one of the star stations of the Colo- 
rado Wireless Association, and of which 
you have all read in a previous issue of 



By W. H. KIR WAN (9XE), 
Master Radio Relays, Radio League of America. 

issued some years ago to Captain Smith ; 
however, the station really belongs to, and 
was made by, Mr. Doig, as explained above. 

A record of messages handled at 9ZF 
from January 13th to March 18th, 1917, 
shows that 251 messages were received and 
sent. A number of them were transcon- 
tinental messages from coast to coast. 
Station 9ZF held a very strategic position 
in the Washington's Birthday Relay of 
February 24th, 1917, and without the as- 
sistance of this station it would not have 
been possible to have sent the message 
thru from coast to coast, nor for the re- 
turn message to have been brought back. 

We believe that nearly all of the stations 
thruout the United States can well pattern 
their installations, as far as general ar- 



in the photograph of the equipment. 

There are three towers to Station 9ZF, 
one of them being 90' high and the other 
two 75' high. One aerial has six No. 12 
aluminum wires, 150' long, and the other 
aerial has four stranded aluminum cables 
with 7 strands of No. 14 in each cable, and 
is 200' long. Both of these aerials are 
connected L type. 

This station has been working regularly 
with amateur stations on both the Atlantic 
and Pacific coasts. Working with 6EA in 
Los Angeles, Cal., has been a continuous 
past performance, and recently this station 
has worked directly with 2PM in New 
York City. We claim that this is truly 
wonderful work for an amateur station, 
and we do not think that there will be 




The Trophy Cup for the Best "Amateur Wireless Station" in the United States Has Been Awarded to Station 9ZF, operated by Messrs. 

E. F. Doig (at Right) and W. H. Smith (Left), of Denver, Colorado. 



this magazine. The winner is Mr. E. F. 
Doig, of No. 848 South Emerson Street, 
Denver, Colo. Mr. Doig made nearly all 
his apparatus himself, and has been assist- 
ed by Mr. W. H. Smith of the Y. M. C. A. 
Radio Club and the Colorado Wireless 
Association. Mr. Doig was for four years 
Master Signal Electrician in the Signal 
Corps of the Colorado National Guard. He 
now holds a special receiving and sending 
license from the United States Govern- 
ment. His equipment, altho not as large 
as the Government station, is very com- 
plete, as you can clearly see from the 
photograph. 

Mr. W. H. Smith, also well known for 
his skill as an operator, is associated with 
Mr. Doig and has worked on his night shift 
at this station. Mr. Doig is also secretary 
of the Colorado Wireless Association and 
Mr. Smith is the chief operator. This 
station will hold this cup for one year, 
and if they win it again in 1918 it will 
belong to this station absolutely. 

The cup has been properly engraved and 
you will see a picture in this magazine 
shortly of the cup holding a prominent 
place in the Laboratory of Mr. Doig. The 
Government Call Book gives Station 9ZF 
as belonging to Captain Smith of the Colo- 
rado National Guard, but the license was 



rangement and efficiency is concerned, after 
Station 9ZF. Another point in favor of 
9ZF was the fact that, while this station 
was affiliated with nearly every Radio Club 
and organization extant, the owners never 
refused a message, nor did they feel that 
Station 9ZF was too proud to work with 
anyone. 

In the receiving cabinet is a large loose 
coupler for reception of long wave stations 
like WG, GW, SL, OUI and POZ, as well 
as the Government arc stations. A smaller 
receiving cabinet is used for the shorter 
wave stations, including the commercial 
coast and sub-stations on the spark sys- 
tem. There is also a short wave regenera- 
tive receiver, which is used in working with 
the amateur stations. This cabinet also 
contains an amplifier which can be used 
in connection with each of the other sets. 
There is not much to tell about the Rotary 
Quenched Gap, as the cut shows just what 
it is, and there are not very many ama- 
teurs but what have had the chance to read 
about this outfit. 

The 1 k.w. outfit which is used mostly, 
radiates from 12 to 14 amperes on a wave 
length of 425 meters, and the oscillation 
transformer is made with edgewise wound 
copper strip, a type with which you are 
all familiar, and which is clearly shown 



any question whatever but that Station 9ZF 
is well entitled to the prize. 

Since holding the Washington's Birthday 
Relay, which you will all remember was 
held in the interest of preparedness, with 
instructions to all sending stations to in- 
terest all wireless amateurs in the United 
States Radio Coast Reserve, Station 9ZF 
worked the hardest for recruits of any sta- 
tion in the United States. 

We have radio clubs in the United States 
of minor importance, which seem to think 
that they were the only ones that had a 
divine right to exist, who have not, with 
all their membership, done as much good 
work in enlisting the amateurs under the 
Navy Department for coast reserve work 
as Station 9ZF. 

All of the stations have been closed by 
the Navy Department, on account of the 
war, for the period of war, and we believe 
it will be some little time before all of us 
are working again. In order that your 
interest will not lag in wireless work, and 
for the benefit of the many amateurs who 
have enlisted thruout the country and are 
now assigned to the various warships, we 
will continue these write-ups each month, 
with something of interest to them, and 
something to remind them of home and 
(Continued on page 143) 



108 



THE ELECTRICAL EXPERIMENTER 



June, 1917 




Notice to All Radio Readers 

As most of our radio readers arc undoubtedly azvare, the U. S. Government has decided that all Amateur Wireless Stations, 
whether licensed or unlicensed, or cquipt for receiving or transmitting, shall be closed. 

This is a very important consideration, especially to those who are readers of THE ELECTRICAL EXPERIMENTER, 
for the reason that we desire to continue to publish valuable articles in the zvireless art from time to time, and which may 
treat on both transmitting and receiving apparatus. In the first place, there arc a great many students among our readers 
who will demand and expect a continuation of the usual class of Radio subjects, which we have publisht in the past four 
years, and secondly, there will be hundreds and even thousands of new radio pupils in the various naval and civilian schools 
thruout the country, zvho will be benefited by up-to-date wireless articles treating on both the transmitting as well as receiv- 
ing equipment. 

Therefore, and in view of the foregoing explanation, we feel sure that every reader will thoroly understand that altho 
articles on transmitting, as well as receiving, apparatus may appear from time to time in these columns, he is not permitted to 
connect up any radio apparatus whatsoever to any form of aeriah — The Editors. 



The Naval Radio Operator 



SCHOOLS are established at the Navy 
Yards at New York and San Fran- 
cisco for the purpose of furnishing 
Radio Electricians for the fleet 
from the enlisted personnel of the 
Navy. After the required sea serv- 
ice has been performed such electricians 
are transferred to shore duty at Naval 
Radio stations and other places. 

The electrical branch of the schools is 
divided into two parts. One branch for 
general electricians and the other for radio 
(wireless). Applicants capable of passing 



radio telegraphy may be enlisted as lands- 
men for Radio Electrician. The applicant 
must be able to take dictation at the speed 
of twenty-five words per minute and pass 




centage and square root. Testimonials as 
to the good character and skill of the 
applicant as an operator must be presented 
either from a former employer or from 
the principal of a school where the appli- 
cant has been a student of radio or teleg- 
raphy. The applicant must be able to 
receive about twenty words a minute. 

In addition to the above, men holding 
commercial radio licenses and who pass an 
additional examination at the Electrical 
School, Navy Yard, New York, or Mare 
Island, Cal., may be enlisted as electricians 




Future Naval Radio Men Learning How to 
Measure Length and Frequency of Etheric 
Waves. 



the examination are enlisted as landsman 
for electrician (either general or radio) 
and are detailed for a course at the Elec- 
trical School. The pay of landsman for 
electrician is $17.60 per month while under 
instruction and in addition he is furnished 
with a complete outfit of uniform, board, 
lodging, text books, tools, and materials 
with which to work. The length of the 
course is about eight months. Upon com- 
pletion of the course at the school the 
men who are qualified are given the rating 
of electrician third class (radio). In both 
courses the following subjects are covered : 
machine shop work, electricity; magnetism, 
alternating currents, dynamos, motors, and 
batteries. It also embraces the principles 
and management of radio stations and in- 
stallations. The general course covers the 
application of electricity to shipboard appli- 
ances. 

Competent operators of the Morse code 
or men with a sufficient foundation in 



Top:— Naval Radio Operator Handling 2 k. w. 

Transmitter. 
Below:— One of the Up-to-Rate Radio Sets 
Which U. S. Naval Operators Learn to Handle 

a creditable examination in spelling and 
penmanship. 

The problems in arithmetic include mul- 
tiplication, division, simple proportion, per- 



Operating Room of Radio Class at the Navy 
School, Brooklyn, New York. 

third class (radio). In both cases, whether 
enlisted as landsmen for electrician or elec- 
trician third class (radio), the regular 
course at the school follows. The oppor- 
tunity for advancement in the Naval Radio 
Service is at present exceptionally good 
and is worthy of consideration by every 
commercial telegraph and radio operator. 

The pay of electricians both general and 
Radio is as follows : Electricians third 
class, $33 per month; Electricians second 
class, $44 per month; Electricians first 
class, $55 per month; Chief Electricians 
(acting appointment), $66 per month, and 
Chief Electricians (permanent appoint- 
ment), $77 per month. This pay is in- 
creased with each enlistment. 

The present policy in the fleet is to ad- 
vance electricians third class (radio) to 
electricians second class at the end of a 
year if their proficiency mark is at least 
3.2. Electricians third class (radio) serve 
(Continued on opposite page) 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



109 



NEW RADIO TRANSMITTER FOR 
U. S. "MOSQUITO" FLEET. 

The accompanying photograph shows a 
complete radio transmitter operated from 




One of the Latest Designs of Ex- 
tremely Compact and Light Weight 
Radio Outfits Intended for "Mos- 
quito" Fleet Service. 



a current derived from a storage battery. 
It was designed for supplying the mos- 
quito fleet with an efficient low power 
transmitting outfit. 

This outfit was developed by A. B. Cole, 
a New York radio engineer. It consists 
of a quenched spark gap of the open air 
type which is mounted on the panel. The 
sparking surface consists of two large spe- 
cial alloyed discs. The gap is excited by 
a spark coil of unique design ; this is placed 
behind the panel, its interrupter, which is 
of the independent type, being stationed on 
the front of the panel and visible on the 
center right. The oscillating circuit con- 
sists of the usual arrangements ; namely, a 

on the large vessels and Electricians sec- 
ond class are sent in charge of the installa- 
tion on destroyers and gunboats. Men who 
have served two years at sea, in radio, 
and who have advanced to second class 
are eligible for shore duty. The pay and 
allowances and retired pay of the Navy, 
and the fact that all men get shore duty, 
makes the Naval Radio Service more at- 
tractive than that of the commercial ser- 
vices. A comparison of the two pays and 
allowances in the Naval Radio and Com- 
mercial Radio favors the former. 

The physical and moral qualifications re- 
quired_ for entrance to the Naval Service 
apply in all respects to these branches. If 
the recruit is unable to complete the course 
of instruction at the Electrical School be- 
cause of incompetency or inaptitude he will 
be transferred, if he desires, to such rating 
in the general service as he is qualified to 
fill or he will be discharged from the Navy 
for inaptitude. 

(Continued on page 153) 



high tension glass condenser and aerial in- 
ductance. A transfer switch is also pro- 
vided for permitting the receiving and 
transmitting instruments to be connected 
at any time desired. This is shown in 
the upper right hand corner. A hot wire 
ammeter is also furnished, and this is 
seen in the upper center of the panel. 

The three plugs at the bottom are used 
for several purposes ; the left hand one is 
employed for connecting the receiving in- 
struments with the aerial ; the center one 
connects the key with the primary of the 
coil and battery, and the right-hand plug 
links the storage battery with the supply 
source. The plug at the upper left hand 
corner is used for connecting the power 
source with the test buzzer of the receiving 
set. A set of binding posts are furnished 
for connecting the aerial and ground with 
the set, and these are seen at the upper 
part of the panel, each being fitted with 
the proper name-plate. 

During some recent tests, the outfit has 
proven to be very efficient. 



THE JAPANESE T. Y. K. 
RADIOPHONE SYSTEM. 

Among the early distinguished workers 
in radiophony we find that Messrs. Wichi 




The Simple Connections Used in the 
Japanese "T. Y. K." Radiophone 
System. 

Torikata, E. Yokoyama and M. Kitamura 
of Japan have done very notable work 
in this direction, and the system which 
they have evolved is a radio frequency 
spark system of unique design, which we 
herewith describe in detail. 

The complete equipment is shown in 
the photograph and resembles very much 
an ordinary standard "wall telephone." 
The transmitting apparatus outside the 
generator is enclosed within the top 
cabinet, while the bottom one contains 
the receiving instruments and aerial con- 
trol switch. The direct current rotary 
converter is seen standing on the floor. 
It runs on a 110-volt direct current source, 
and delivers 500 volts D. C. for the arc. 
Protective resistances and choke coil are 
used, and these are mounted on a sepa- 
rate base ; they are seen below the in- 
strument proper. 

The transmitting equipment consists of 
a specially constructed arc, its electrodes 
consisting of iron and brass. The dis- 
tance between the stationary and movable 
electrodes are automatically controlled 
by means of an electro-magnet so ar- 
ranged as to adjust the arc terminals in 
order to keep the oscillatory condition 
operative. This arc is operated in the 
open air and. the same is mounted on top 
of the transmitting cabinet. Its connec- 
tions are made thru the control electro- 
magnets of the cquilibrator, as indicated in 
the wiring diagram. The movable elec- 



trode G is controlled by an armature H, 
which is acted upon by the electro-magnet. 
The contact I, is broken as soon as the 
arc has properly started. This break of 
current at I, is due to the decrease of 
the arc resistance which permits a large 
steady flow of current thru the coil, con- 
sequently attracting the contact. The arc 
is shunted with the usual type of oscil- 
latory circuit, P.V.C., namely, the primary 
of an oscillation transformer, which in- 
ductance is controlled by means of the 
side switch on the left of the transmitting 
cabinet. A variable high-tension condenser 
is also mounted in the same cabinet and 
its capacity is varied by means of a multi- 
ple-point switch, indicated on the front. 
An ordinary carbon microphone is linked 
in the ground circuit of the secondary of 
the oscillation transformer, as shown in 
the wiring diagram. This microphone is 
stationed on a movable bracket on the 
front of the cabinet. 

The receiving equipment is inclosed in 
the lower compartment and consists of a 
standard loose coupled receiver, with a 
crystal detector. This is placed in a metal 
housing equipt with a metal door, seen 
on the left of the case. Adjusting the 
crystal is performed by a vertical rod pro- 
truding from the top cover. Two variable 
condensers are used and these are mounted 
on top, while the coupling of the primary 
and secondary is varied by turning the 
front knob. A change-over switch is sup- 
plied for connecting the receiving and 
transmitting instruments whenever de- 
sired, and the control handle for the same 
is seen at rear, left-hand corner of the 
lower cabinet. The primary switch is 
mounted on the left. 

Excellent results were obtained with this 
system, and a number of sets have been 
installed in several Japanese land and boat 




The Japanese "T. Y. K." Wireless Phone 
System Is One of the Simplest and Most 
Efficient Ever Devised. It Greatly Re- 
sembles the Familiar "Wall" Type Tele- 
phone. 

stations. The efficiency in watts per mile 
of talking range is remarkably high. Also 
the design of the complete equipment is 
marked by distinctive simplicity. 



110 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



Remarkable Radio Outfit Built By German Spy 



A LITTLE black box of mystery, 
seized recently by the police in the 
belief that it was nothing more 
than a modern adaptation of a time 
worn contrivance for swindling un- 
sophisticated persons out of their savings, 




U. S. Government 
and Police Experts 
Were Much Sur- 
prised to Find That 
the Cabinet Here 
Shown, Which Was 
Recently Seized 
with Max Wax, a 
German Spy, Was 
Capable of Receiv- 
ing Secret Radio 
Messages from 
Germany. 



was revealed as a clever wireless telegraph 
outfit, capable of receiving messages from 
as far away as Berlin. 

Police and government experts who ex- 
amined the mechanism in the box declared 
it to be as perfect in construction as any 
they ever had seen. It is (or was) the 
property of Max Hans Ludwig Wax, a 
German citizen, and graduate of the Uni- 
versity of Berlin. Wax, as soon as he 
found the police had learned the real nature 
of the intricate contents of the box, as- 
sumed an air of stolid indifference, denied 
he knew the box could lie of service either 
in sending or receiving telegraph messages 
or that he knew anything of telegraphy, and 
asserted that apparently useless bits of par- 
aphernalia contained in the box had been 
placed there by him merely to make the 
contrivance "look pretty." 

Then, the police say, Wax informed pros- 
pective dupes that the little black box con- 
tained machinery devised by German scien- 
tists for reproducing American banknotes 
and currency bills. If he would place a one- 
thousand dollar bill in the "press"' inside the 
box the contrivance would print ten dupli- 
cates of that bill. It then was the duty of 
the "loyal'' German, the police say they 
were informed, to pass the spurious notes 
off for American gold, so that eventually 
this country would be flooded with counter- 
feit notes and persons loyal to Germany 
would be in possession of most of this 
country's gold. 

Just after Wax was arrested the police 
learned that he had left the box in a ma- 
chine shop in New York City. The police 
finally located the box in a trunk which 
they said was equipt with a false bottom. 
It was not until Sergeant Pierce, in charge 
of the police wireless station, rigged up as 
part of the scheme for military defence 



by Arthur Woods, Police Commissioner, 
looked at the contrivance that it was recog- 
nized as a genuine and extremely effective 
portable wireless outfit. 

The box is about two and a half feet 
square. It is covered with black enamel and 
has silver handles and 
^mmm— — — j brass hinges and 
BBHUfck. S clasp. It must have 
Kkl cost at least $800, ac- 
|j cording to the esti- 
K~3m mate of experts. 
•jffjBlB • As soon as Ser- 
PM E r B HHBI ¥ . geant Pierce recog- 
8™ nized the use to which 
the queer arrange- 
ment might be put 
the outfit was rigged 
up, its batteries were 
set in motion, and in 
a moment the hissing 
sounds and sputtering 
and flashing sparks 
that attend the opera- 
tion of a wireless out- 
fit were in evidence. 

Wax persisted, de- 
spite the effectiveness 
of this demonstra- 
tion, in his assertion 
that the batteries, 
tiny dynamo and in- 
tricate coils were 
placed in the box by 
him to make the ap- 
paratus "look pretty." 
Eventually he said he 
intended to use them 
to give color to a mo- 
tion picture scenario 
he intended to write. 

Persistent question- 
ing, however, drew 
from Wax, according 
to the police state- 
ment, the admission that he, having bought 
the materials, the box and its out'fit were put 
together for him by a seaman on board one 
of the interned German ships lying at Ho- 
boken. He refused to reveal the identity 
of the man, asserting he knew him only as 
"Frank" and had met him only a few times. 

When the examination of Wax had pro- 
ceeded that far L. R. Krum, chief radio 
officer of the federal government for the 
New York district, arrived at Police Head- 
quarters. He examined the machinery con- 
tained in the box carefully and then verified 
Sergeant Pierce's declaration that it was a 
wireless outfit of great strength. He agreed 
with Sergeant Pierce that the apparatus 
was easily capable of receiving messages 
from as far away as Berlin. Both experts, 
however, declared the apparatus probably 
could not be used to send a message much 
farther than one hundred miles. 

Despite the readiness with which Mr. 
Krum and the police wireless operators 
were able to set the wireless outfit in mo- 
tion, many contrivances in the box were a 
mystery to them. It appeared as if there 
were three sets of batteries, where only one 
was necessary. The operators exprest the 
belief, however, that any one of the three 
battery sets might have been connected with 
the rest of the apparatus, so that, even if 
two batteries failed, there still would be 
power to keep the contrivance in operation. 

The only incomplete thing about the out- 
fit was that the police were unable to find a 
sending key and a transformer, both of 
which would be necessary if the machine 
were to be used for sending wireless mes- 
sages. Wax, however, is described by per- 
sons who stayed in the house where he lived 
as having been in the habit of carrying a 
small hand grip. The grip has not yet been 
found. 



After the police were satisfied of the na- 
ture of the equipment in the box they asked 
Wax to operate it. He fingered several 
parts of the mechanism for a moment or 
two and finally succeeded in causing a short 
circuit, which effectually put the whole thing 
out of commission. The damage, however, 
can be repaired easily. 

In the examination of Wax the police 
drew from him the statement that he came 
to this country from Germany in June, 
1914. 

He denied he had served in the German 
army, asserting he was rejected for mili- 
tary service because he had a weak heart. 
Dr. Baker and Dr. Hamilton, police sur- 
geons, were called in to examine the pris- 
oner. They pronounced him an almost 
perfect physical specimen and said there 
was no indication that he ever had suffered 
from heart disease. 

Considerable interest was manifested by 
the police and federal investigators in 
papers and letters found in Wax's posses- 
sion. They declared some were written in 
code. All of them were in duplicate. One 
of the papers, according to the police, was a 
draft for $12,000 and another was for 2,300 
marks. The latter was drawn on the 
Deutsche Bank, of Berlin. It was declared 
by the police that Wax received some of 
these papers thru the office of the German 
Consul in this city several weeks ago. The 
money, the police said they learned, was sent 
to _ Wax by relatives in Germany, who the 
prisoner declared were both wealthy and 
influential there. 



ELECTRICITY REDUCES FIRE 
HAZARD. 

One-fourth of all the fires occurring in 
Waterbury, . Conn., for a year might have 
been avoided by the use of electricity, 
according to the report of Fire Chief 
Heitman. 



A NEW VACUUM CURRENT GAGE 
FOR RADIO. 

Herewith we present the vacuum am- 
pere gage, a new Marconi device. 

The demand for a small, sensitive, ro- 
bust instrument ' suitable for use equally 
on alternating and continuous current cir- 
cuits is not new, and inventors have made 
many attempts to satisfy it. 

The instrument is designed primarily as 
a maximum current gage to indicate the 
condition of syntony in wireless circuits, 
and may be employed as a substitute for a 
ihcrmo- junction and galvanometer com- 
bination in the measurement of wave 
lengths and decrement. The principle in- 



tloir^Spring 




Support 



fi/omenk 



By Placing the Delicate Moving Parts of 
This High Frequency Current Gage in an 
Evacuated Bulb the Action is Made More 
Stable and Reliable. It Can Be Used with 
a Wave Meter to Measure the "Decre- 
ment." 

volved is that of the bifilar suspension, one 
pair of the filament ends being fixt, and the 
other pair attached to a pivoted arm, the 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



111 



rotation of which is controlled by a spring 
acting against the tension of the filaments. 
When a current passes thru the filaments, 
heating them and causing them to elongate, 
the arm takes up a new position and the 
angular displacement as indicated on the 
scale is a measurement of the current. 

The movement is enclosed in a glass bulb 
exhausted of air. The sensitiveness is thus 
greatly increased, and the movement pro- 
tected against damage and preserved from 
dust or corrosion. 

The drawing shows quite clearly the con- 
struction of the little instrument, which is 
made up in such a way as to resemble an 
electric lamp. In one form the bulb is 
attached to a brass cap with projecting 
pins identical with that used on standard 
English lamp bulbs, and the size of the 
instrument can be gaged by noticing this 
feature in the drawing. 

The variation in zero which is character- 
istic of hot wire instruments in general is 
negligible in this type of instrument, and 
the natural damping renders the move- 
ment especially dead-beat. 

The instrument, suitably calibrated, may 
also be used as a low reading volt-meter or 
ammeter, or as a shunted ammeter. The 
normal resistance of the commercial type 
of vacuum instrument is approximately 12 
ohms. 

Enclosing the working parts in a vacuum 
has enabled the makers to place on the 
market an instrument which should prove 
of great general utility on account of the 
fact that, at a reasonable cost, it is pos- 
sible to provide the means of measuring 
direct and alternating currents of the or- 
der of .01 amp., without sacrificing any 
robustness of construction. The small size 
makes it a matter of no particular diffi- 
culty to insert the instrument in a circuit 
where no previous provision has been made 
for a measuring instrument. 

With a wave meter using the new vacu- 
um gage the wave-length of the primary 
circuit of a 1^2-kw. set can quite easily be 
read when the wave meter is held with the 
plane of its inductance coils parallel to 
that of the primary of the oscillation trans- 
former at a distance of two to three feet. 
The noise of the spark, which often hin- 
ders the reading of a wave meter by means 
of a crystal and telephones, in the case of 
the vacuum gage gives no trouble, as the 
variable condenser has simply to be rotated 
until_ the pointer of the gage gives the 
maximum reading. In this way circuits 
can be tuned rapidly as well as accurately. 



MISS WINIFRED DOW A RADIO 
ENTHUSIAST. 

Herewith find picture of my radio ex- 
perimental outfit. My receiving set con- 




sists of a Murdock variable condenser, ai 
Audion and variometer. 

With this set I hear the calls of KPH 
KPA; NPC; NPE and of course all Ama 
teurs in this vicinity. 

At the present ...... ,. , . „ 

t „„, Mlss Margaret L. Campbell, of Rock- 
time 1 am Using portj Mass., Has Long Been a Radio 
only a spark COll Enthusiast and Has Operated the Ap- 

and dry cells for P ar j? tus Sh ° w " _ °n Frequent Trips 

. i. . , , Made on Her Father's Yacht. She 

transmitting DUt Has Achieved a Distinct Success with 

have a 1 kilowatt Her Station, Having Become Thoroly 

set nearly com- Conversant with All Radio Matters. 

plete. 

I thank you in 
advance for the 
interest you have 
taken. Wirelessly 
yours, Winifred 
Dow, Tacoma, 
Wash. 



"THE CRUISE"— A RADIO STORY. 
By MARGARET L. CAMPBELL. 

Early in August, 1916, I transferred my 
wireless set from my radio station to my 



There are lots 
of worse jobs 
than that of Ra- 
dio operator for 
Uncle Sam. Be- 
sides, he pays 
you while learn- 
ing. Why not in- 
quire about it ? 
Both women and 
men are eligible. 




MRS. CANDLER AN ABLE RADIO 
OPERATOR. 

Mrs. Candler of St. Marys, Ohio, says, 
"I surely am very much interested in wire- 
less and not only interested but have been 
operating our set ever since it has been 
in existence. I now hold a first grade com- 
mercial license. The first photo of our set 
was sent you last year by '9XE' and ap- 
peared in the Experimenter in connection 
with the report of the Washington's Birth- 
There Is Now an Opportunity 
for All Radio Women. One 
of the Best Qualified Opera- 
tors Is Mrs. Chas. Candler, 
of St. Marys, Ohio. 




day Relay in the May, 1916, issue. This 
year our station (8NH") again took prom- 
inent part in the Presidential Relay, being 
a prize winner. We have been subscrib- 
ers to the Electrical Experimenter for 
more than a year." 



Among the Girls "Radio" Has Now Become 
a Promising Vocation. At Least Miss Wini- 
fred Dow, of Tacoma, Wash., Seems to 
Think So. 



PHILADELPHIA'S NEW RADIO 
STATION WILL SEND THREE- 
FOURTHS WAY AROUND 
WORLD. 

Preliminary wor£ on construction of one 
of the most powerful wireless stations in 
the world has begun at the Philadelphia 
Navy Yard, according to an official an- 
nouncement made recently. The construc- 
tion of a hangar which will house eight 
battle hydroairplanes also is under way. 

The new wireless station will have a 
sending radius of approximately three- 
fourths of the distance around the globe, 
making possible direct communication with 
the Philippines and other insular possessions 
of the United States. The aerial structure 
will be more than 700 feet high. 



father's new_ sixty foot yacht, the Wa- 
liama. She is a flush deck cruiser with 
all modern improvements and powered 
with a large four-cycle gasoline engine. 
She also has two masts about thirty-five 
feet apart, which I used to support my 
aerial. There is a large cabin, ten by twelve 
feet in size, in which I installed my trans- 
mitting and receiving apparatus, which con- 
sists of a two inch spark coil, two Leyden 
jars, helix, spark gap and key. Also, two 
variable condensers, loose coupler, tuning 
coil, loading inductance, Ferron, galena and 
silicon detectors mounted upon a movable 
cabinet. 

One of the interesting cruises made last 
summer was with a company of Marine 
Boy Scouts of which my father is the 
fa commander. We sailed along the coast 
of Massachusetts Bay, visiting vari- 
ous harbors and spending several days 
in Marblehead harbor during the fes- 
tivities of "Marblehead Week," when 
the great racing events of that notable 
yachting center are held. 
The harbor was filled with yachts of all 
types and age ; from the majestic steam 
yacht of the millionaire to the small sailing 
dory of some aspiring youth. I was sur- 
prised to find how few of these boats were 
equipt with wireless apparatus, also how 
few of them so equipt appeared to be using 
their apparatus or even listening in. I 
held conversation with some interested 
amateurs on shore. 

We did not send or receive any "S.O.S." 
calls, but did have occasion to render timely 
assistance to a motor boat whose engine 
had broken down out at sea and towed 
her to a place of safety before a severe 
thunder storm broke upon us. 

I might say that I detected little differ- 
ence in the workings of my apparatus 
aboard the boat as compared with the 
same on land. 

I found my set to be of the greatest 
service in the evening when the crew gath- 
ered about to get the time signals and the 
news of the day. 



WIRELESS TELEGRAPHY ON 
BRITISH SHIPS. 

By an Order in Council, issued on July 
28 last, every British ship of 3,000 tons 
gross or upwards is required to have a 
wireless installation. 



112 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



The Marconi Type "106" Tuner 



THE receiver consists of a type "106'' 
tuner and a crystal detector. This 
receiver consists of a variable induct- 
ance primary circuit. One end of this 
inductance is connected to the antenna thru 



By WORTH MacKNIGHT 

The switches marked Transformer Pri- 
mary are for the purpose of varying the 
amount of inductance in the aerial circuit. 
The switch marked Units varies the induc- 
tance in one-turn steps. The switch marked 




F/g.l 



Front View of the "Marconi" Type 106 Radio Receiving Cabinet. 

Will Find It Beneficial to Study It Thoroly. 

the antenna switch. The other end of the 
inductance is connected to the ground thru 
a variable condenser, which can be short- 
circuited or thrown into circuit at will. The 
secondary circuit is so constructed that its 
inductance may be varied, and also its in- 
ductive relation with the primary circuit 
can be changed. A variable condenser is 
provided, which permits a variation of wave 
length and also the variation of the ratio 
capacity to the inductance, while maintain- 
ing the same wave length. A battery and 
potentiometer is provided which permits 
controlling the current thru the detector. A 
pair of head telephones is used for receiv- 
ing the signals. A buzzer is supplied which 
permits the local excitation of this receiver, 
so as to determine its condition of sensi- 
tiveness. A battery furnishes current for 
both the detector and buzzer. 

Fig. 1 is a front view of the type "106" 
tuner and shows the exact position of the 
different switches and parts for its opera- 
tion. 



Radio Students 



aerial is connected to one terminal of the 
inductance, so that by varying the trans- 
former primary, a greater or less amount of 
inductance can be inserted between the. 
aerial and ground. This either increases or 
decreases the natural period of the primary 
or aerial circuit. It is necessary, therefore, 
to make these adjustments to bring the cir- 
cuit in tune with the received signals. If 
the wave length of the received signal is 
shorter than that of the aerial circuit, it is 
necessary to insert the primary condenser in 
the circuit. This has the effect of shorten- 
ing the time period of this circuit. The 
secondary circuit consists of a variable 
condenser marked Secondary Condenser, 
and a variable inductance marked Trans- 
former Secondary. 

By varying either the transformer sec- 
ondary switch or the secondary condenser, 
this circuit can be tuned to the wave length 
of the incoming signals. It is also possible 
to vary the ratio of capacity to inductance, 
while maintaining the same wave length 
adjustment. It is often found to advantage 
to vary this ratio. The handle marked 
Coupling is for the purpose of varying the 
inductive relation of the primary circuit and 
the secondary circuit. After these circuits 
have been tuned to the incoming signals, 
the coupling should be varied until a maxi- 
mum response is found. The handle 




Front View of "Marconi" Type 106 Radio Receiving Cabinet, Equipt with Mineral 
Detector and Loose Coupler. 




fig.. 



Pofenf/ometer 





4"lwwv — -^ 



/ 

Buzzer 



Hook-Up for Complete "Marconi" Type 106 Receiving Set, Showing 
Inductively Coupled Test Buzzer. 



Tens varies this 
inductance in ten- 
turn steps. The 
Primary Conden- 
ser, when in zero 
position, has a 
minimum capacity. 
If this condenser 
is turned beyond 
the 180 degree 
mark, it automati- 
cally short-circuits 
itself, so that the 
aerial circuit will 
have no series ca- 
pacity in it. The 
terminal marked 
Aerial is connect- 
ed to the antenna 
switch. The ter- 
minal marked 
Ground is connect- 
ed to the ground. 
When this primary 
circuit is connect- 
ed to the aerial and 
ground the circuit 
is as follows : The 



marked Potentiometer varies the current 
thru the crystal detector. The detector is 
situated between the coupling and conden- 
ser handles. A switch marked Battery 'is 
provided, so that the crystal may be used 
either with or without the battery. A buz- 
zer is mounted on the front of the panel 
and is operated with a button marked Test. 
Terminals are provided to connect to the 
battery; they are marked Battery. Two 
terminals are provided for connecting in 
the telephone receivers, and are marked 
Telephones. 

The internal as well as the external con- 
nections of this receiver are shown in Fig. 
3. Fig. 2 is a back view of the panel. 

This hook-up is of interest to all radio 
amateurs and students who expect some 
day to become commercial operators. 
Among other things, note that the buzzer 
test is linked up with the aerial-ground cir- 
cuit inductively by a two coil transformer. 
Note how the secondary coil is moved in 
and out of the primary by a rack and pinion 
arrangement, giving great precision to the 
coupling adjustments as well as rotary con- 
trol. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



113 



The How and Why of Radio Apparatus 




r!f Zinc electrodes 

y. 



— ^ x tond 



NO. 4— SPARK GAPS. 

From* lime to time we will describe one 
particular instrument used in either the ra- 
dio transmitting or receiving set, explain- 
ing just how it works, and why. We have 
received so many requests from new read- 
ers asking for such explanations, that we 
have decided to publish this matter in serial 
form. In the course of several issues all of 
the principal transmitting and receiving ap- 
paratus zvill have been covered. The subject 
for the fourth paper is the SPARK GAP. 

THE spark gap forms one of the 
most important parts of any os- 
cillatory circuit, and this proves 
particularly so in radio transmit- 
ting circuits, where everything 
must be designed to realize the utmost ef- 
ficiency. This means careful and scientific 
design at every turn, and it takes into con- 
sideration such important topics as the 
proper dissipa- 
tion of the heat 
produced in the 
gap ; the proper 
arrangement o f 
the gap to give 
the desired tone, 
and a number of 
other vital points. 

The part played 
by the spark gap 
in an oscillatory 
circuit is to allow 
the condenser in 
this circuit to 
charge to the re- 
quired voltage, 
and then to break 
down and permit 
the charge stored 
in the condenser, 
to surge back 
and forth across 
the gap in the 
form of sparks, 
until all of its 
energy is dissi- 
pated. For sev- 
eral reasons the 
ideal spark gap 
would be one 
which would in- 
sulate perfectly, 
or be 11011 - con- 
ducting during 
the time when 
the condenser 
was being 
charged, and con- 
ducting perfectly, 

while the condenser was discharging. 

The nearer these requirements are ful- 
filled in any spark gap, the more efficient 
will this piece of apparatus perform its 
function. While the discharge is passing, 
the resistance of the gap depends upon 
two factors : the resistance increasing 
markedly with the length of the spark, 
and decreasing rapidly with the oscillatory 
current, amounting with a half-inch gap 
to several hundred ohms when a fraction 
of an ampere passes, and but a small frac- 
tion of an ohm when say sixty amperes 
flow across the gap. If the spark length 
is above one-half inch, the resistance with 
the same oscillatory current flowing, can 
be taken as approximately proportional to 
the spark length. However, in a condens- 
er circuit, the quantity of electricity is 
stored up in the condenser, and in conse- 
quence, the amount of oscillatory current 
increases with the spark length. Hence, 
we find two conditions working against 
each other, as regards the influence of the 
spark length on the spark resistance. 



However, we can increase the amount of 
current passing thru the gap without in- 
creasing the length of the spark, by simply 
increasing the size of the condenser, and 
the most efficient circuit for a given amount 
of power, is that in which there is a mod- 
erate spark length with a large condenser. 

When the condenser has been fully 
charged, the spark gap breaks down, and the 
gap becomes filled with metallic vapor, and 
for the time being forms a high frequency 
alternating-current arc. The conductivity 
of the spark is due to the presence of me- 
tallic vapor in the gap. After the discharge- 
ceases, and if this metallic vapor is not 
quickly removed from the gap, the insula- 
tion will in consequence be very low at 
the time that the condenser is passing thru 
its next charging period, which of course 
occurs in a small fraction of a second, usu- 
ally. 

It is therefore paramount that we re- 



any indefinite time, it is best with such 
non-synchronous rotary gaps, to provide a 

stationary electrode "A," in the form of a 
segment, having a pitch equal to the dis- 
tance between two of the rotary electrode 
points. 

For synchronous rotary gaps, driven by a 
synchronous A.C. motor or by mounting 
the disc on the same shaft with the motor- 
generator, as is done in the best types of 
commercial radio transmitting sets, the fixt 
electrodes need not be any larger than a 
single electrode point on the rotary disc. 

One of the most efficient spark gaps used 
very successfully by commercial stations 
and also by numerous amateurs, is the 
quenched gap illustrated at Fig. 3. This 
gap, which is very well known to-day, is 
designed on several important basic prin- 
ciples. The foremost of these desidera- 
tums is that each gap shall be preferably 
not over 1/100 of an inch in length, and 
moreover, that 



Coo/mg Vanes 
SparAgap 



Spark gap 



Zinc Electrodes 
Threaded in 





Trf Sec 




Grooves ■ 



fW>l Cooling ranges 




Fig. 2 

Segments, fat /Rotaru plate 
j (Plate 7 

•»>\i)!m//d/^ /Airtight casing 
- - 1Y Adjustable 
bo// bearings 



WIPE 



Cooling^ 
Vanes 




Cost or turned plates 



F//.J plate 




Ins u I. coupling 

Mo/orshaf/ 
003' ' spA gap. 



Fig. 3 



Fig. 4 



Various Styles of Radio 
Sets. The Rotary Quenc 



Spark Gaps Which Have Been Found Efficie 
hed Gap, Fig. 4, Is One of the Best for Small 
Operating on Low Frequency Circuits. 

move this vapor completely as soon as pos- 
sible after the discharges of the condenser 
have ceased. This has been attempted in 
various ways in the past, such as by pro- 
viding spark gaps having large cooling 
vanes attached to the spark electrodes, as 
in Fig. 1, and also by causing one or both 
of the spark gap electrodes to rapidly ro- 
tate, so as to constantly refresh the air in 
the gap. This latter condition, which is 
usually met by arranging a number of 
small spark electrodes on a rotary disc at- 
tached to the shaft of a motor, or to the 
shaft of a motor-generator in the case of 
synchronous spark gaps, the spark being 
caused to jump thru the air between the 
constantly moving electrodes, and one, or 
more fixt electrodes mounted on the base 
of the spark gap. 

Fig. 2 shows a non-synchronous type of 
spark gap in which the speed of the rotat- 
ing disc bears no definite relation to the 
frequency of the alternating-current in the 
transformer or spark coil. As a spark is 
apt to occur, or want to occur, at most 



the gap shall be 
absolutely air- 
tight. Further, 
not over 1,000 to 
1,200 volts should 
be applied to 
each individual 
gap, and for high- 
er voltage a suit- 
able number of 
these short gaps 
are placed in se- 
ries, as shown in 
the illustration 
herewith ; two 
gaps being adap- 
ted to 2,000 volts 
— three gaps to 
3,000 volts, etc. 
The action o f 
this gap has been 
described at some 
length in a semi- 
technical manner 
by Mr. Charles 
R. Ballantine in 
the March, 1917, 
issue of The 
Electrical 
Experimenter. 
Briefly, the action 
of the gap is 
based upon the 
fact that a small 
quantity of air 
is trapt between 
the spark sur- 
faces separated 
by a mica ring of 
proper thickness. After the first few sparks 
have past the oxygen in the trapt air is 
burned up, resulting in a partial vacuum in 
the gap. This conduces to the rapid 
quenching thereafter of the spark dis- 
charges, due to the condenser, and gives 
rise to a very ideal set of conditions for 
the entire radio transmitting circuit. This 
is because the oscillations in the spark gap- 
condenser circuit are cut off after the first 
few beats or sparks, but the oscillations in- 
duced in the aerial-ground circuit are left 
free to oscillate for a longer period. This 
prevents the reaction of free oscillations in 
the spark gap circuit upon the aerial or 
secondary circuit — a condition which is in- 
variably found in ordinary radio transmit- 
ters fitted with a plain fixt spark gap, and 
a condition which mitigates seriously 
against the best efficiency of such an equip- 
ment. The quenched spark gap usually 
consists of a number of these small gaps 
as above described, which are placed in a 
suitable frame so that considerable me- 
(Continued on page 153) 



ten 



nt for Different Types of 
and Medium Power Sets 



14 



THE ELECTRICAL EXPERIMENTER 



June, 1917 




BEING cooped up in a flat, late years, 
I've had to give up experimenting. 
Mine's a fine flat, as flats go— all 
modern conveniences, two kinds of 
cold water as the fellow says, and a 
fire-escape with a sparrow's nest on it ; 
even a little safe let into the wall, big 




-Contacts 



ftg.i 



Fig. 1. Attempt No. 1 in Electric Clock 
Research as Tried Out by the Author — Did 
it Work? Read the Accompanying Text if 
You Think So, Bugs. 

enough to hold most of the Wiff's diamond 
tiaras if you pack 'em tight. Yes, it has 
all the conveniences but one, and that's the 
only one worth having — a workshop. 

The nearest I can get to it now is read- 
ing the good old Electrical Experimenter. 
When she blows in, I sop her up from 
front cover to back — every word. Adver- 
tisements and all. Well, I'll say so; and 
I'm not the only one that does it, eh, 
Bugs? 

One place I always stop and smile, and 
that's the heading "How-to-Make-It De- 
partment." I guess my department is the 
"How-A r o?-to-Make-It.'' Usually every- 
thing I started went wrong the first time ; 
but the finding out why it wouldn't work, 
and making it over till it would, wasn't the 
worst fun in the world. In fact, I think 
it was the best. No fun simply copying. 

When it came to the electric clock, 
though, that nearly beat me. There's a 
thing that looks easy, and isn't ; yet it's 
simple enough once you're wised up. 

I was sort of forced into the clock craze. 
You see, our kitchen clock was on the 
blink. Father didn't blame it — good old 
clock, he said, it had served him faithfully 
twenty-five years, and was worn out. Worn 
out nothing! I'll bet old Jerome turned 



The Clock Craze 

By Thomas Reed 

over in his grave at that libel, for one of 
his excellent brass clocks ought to go for 
100 years, and only be talking baby-talk 
then. 1 knew what ailed it all right ; it was 
so full of my contact-springs, wires, mag- 
nets and other junk, that its regular works 
had become discouraged. But that was a 
secret between me and the clock, and there 
were good reasons why the secret was safe 
with me. 

Anyhow, when the clock took to stop- 
ping, something had to be done, and done 
quick, because mother would figure wrong 
with her Saturday baking, and Mrs. Skil- 
lings would get her hot pies out on the 
window-sill first, which was an awful 
catastrophe to mother, and made her feel 
as peevish as the Standard Oil does when a 
competitor sells a quart or so of gasoline 
right under its nose. 

I had pondered a little on electric clocks, 
and as I say they looked easy, so I made 
the family a proposition : for half the 
price of a new clock I would turn the old 
one into • an electric clock that would go 
all the time without winding. Father liked 
the idea because his back got twisted climb- 
ing up on a chair to wind the thing, and 
any clock at all looked good to mother 
provided it was a going institution. I said 
this one you couldn't stop if you wanted 
to ; and it would be so accurate that Mrs. 
Skillings would be running over to ask 
humbly what the really correct time was. 
This is known as promoters' language, and 
is powerful. It clinched the deal. Father 




Magnet 



^Armature 




Attempt No. 2, in Electric Clock Design. 
This Arrangement "Worked Too Well." But 
the Magnet's Successive Pulls on the Pendu- 
lum Accumulated till it Banged Against the 
Magnet Like Jess Willard Administering a 
K. O. 



handed over the kale with a feeling which 
if magnified a few diameters would have 
been enthusiasm. 

Everybody (including myself) expected 
it would be not over two weeks at the out- 
side before I had the clock rigged up and 




Finally the Electric Clock Problem Settled 
Down to a Resurrection of Hipp's Famous 
Pendulum. But Oh! that "Agate" Post !X? 
Likewise Zowie. 



was after Mrs. SkilMngs* goat with it. I 
took the old clock to pieces for the last 
time, pulled out a few superfluous wheels 
and springs, and inserted a pawl and rat- 
chet-wheel where they would do the most 
good. Then I started gaily on the electric 
pendulum that was to drive it. I wished 
afterward I'd made the pendulum first. 

It was a grand pendulum I made — a sec- 
onds-pendulum of the due length of 39.1 
inches, with wooden rod and a fine heavy 
bob. I was so cocksure that I polished up 
all parts as I went along. But when it 
was done, it wouldn't work. 

There were two or three main reasons 
why. To begin with, it was hung on pivots, 
like a telegraph key ; and the heavy bob 
set up so much friction there that it would 
have taken about a kilowatt to drive it. 
Of course it should have been hung on a 
suspension spring, which lets the pendu- 
lum oscillate while supporting its weight 
without friction. Bonehead play number 
one. 

Well, I discarded my pivots — tho I 
hated to, they looked so pretty — and with 
my pendulum swinging easily from a 
spring, I looked to see her go. But nix. 
Good strong magnet, clean contacts, and 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



115 



all that, but nothing doing. Could any- 
thing be wrong with my arrangement? 
Answer, oui, oui. 

You see I had it rigged as in Fig. 1, 
following the idea of the electric bell. 
When the pendulum swung over far enough 
to make contact, the magnet gave a vigor- 
ous pull; but unfortunately it checked the 



guine promoter. My stockholders, ignor- 
ant of the exactions of science, were clam- 
oring for quick returns on their investment. 
Stockholders in this mood fall naturally 
into sarcasm. They say, "Oh, you were 
just as sure as anything when you were 
after our money, and now you admit you 
didn't know what you were doing. Of 
course you're right on 



Pendu/um 
rod 




P/af/nc/m confacr Tfp/n 6er/r?0/7 



ross trigger 



Pocod stee/ 6 rod 
t>enf svff/?/ aog/e 
nofcfied of /o/? 





Conoecf/og w/res 
to bar d /nogrtef 



fig 4 



<2L 



Finally I Contrived a Substitute for that "Agate" Post on the 
Clock Pendulum, Relates the Author, and Decided that the Thing 
to do Was to "Substitute." Steel Proved Excellent — but I Guess 
a Piece of Cheese Would Have Sufficed. 

pendulum just as much as it pulled it, and 
the result was nil. The slow, free-swing- 
ing pendulum acted differently from the 
rapid, springy bell-hammer. 

The two weeks were already up, and 
mother was beginning to peeve, because 
meanwhile Mrs. Skillings had put it over 
her again on the pies ; so I hid my chagrin 
under what I hoped looked like a confident 
smile and attacked the problem anew. 

The next attempt is shown in Fig. 2. I 
made a flapping contact, metal on one side 
and insulating mica on the other. This 
arrangement worked too well, if you get 
me. The magnet gave a nice pull, and on 
the back-stroke it let go, all as per inten- 
tion. But now the pulls accumulated till 
the pendulum ended by banging against the 
magnet like Jess Willard administering a 
K-O. This pendulum thing began to seem 
decidedly not as easy as it used. 

Anyhow, to have it go at all was some 
consolation. All that was needed now was 
some arrangement to cut the current off 
as soon as the pendulum had all the im- 
pulse it needed, and switch it on again 
when more was required. Now I began to 
appreciate Hipp's pendulum, described in 
the text-books. In Hipp's device (Fig. 3) 
the electric contact is made by means of 
a notched post attached to the pendulum, 
which normally pushes past a little swing- 
ing trigger attached to the contact-spring. 
As the pendulum loses its amplitude, there 
comes a moment when the notch in the 
post just catches the trigger, and then when 
it starts the other way the trigger is 
raised and the contact made, the magnet 
is energized, and gives the pendulum a 
push. The notch now brushes by the trig- 
ger again, until the narrowing swings allow 
it to catch once more, and the process is 
repeated. As the battery runs down, the 
push is weaker and the contact has to be 
made oftener; but the mechanism does this 
automatically until the battery is exhausted. 

Hipp's rinktum looked effective, if one 
could only make it ; but being a clock- 
maker, old Hipp had specified agate as the 
material for his notched post. Agate, he 
says, just like that: "Take a piece of agate, 
you know, and put a notch in it." Oh, 
yes. The only agate I had ever heard of 
was an agate marble ; and it didn't look 
exactly like easy stuff to make anything of. 

Four weeks had now gone by, and the 
family had lost all their peevishness ; that, 
is, they had exchanged it for black looks 
and language not calculated to please. I 
was reaping the usual reward of the san- 



the track of it this 
time — pooh, pooh ! 
Have it all ready to- 
morrow morning at 
breakfast, I suppose. 
Well, a fool and his 

money " all that 

encouraging stuff. I 
know just how to 
treat impatient inves- 
tors now ; but at that 
time the situation, 
coming on top of my 
defeat at the hands of 
Nature, got my goat, 
and I'm ashamed to 
say I declared bank- 
ruptcy and quit. 
Father bought a new 
kitchen clock, and is- 
sued a manifesto 
(having got an inkling of what ailed its 
predecessor) that if I monkeyed with its 
insides to the 100th part of a monk, he 
would monkey with my outside ; and, in the 
vigorous language of the day, I was not 
to forget it. 

I knew why a prophet is without honor 
in his own country. Believe me, my home 
reputation as a budding scientific and busi- 
ness man was badly damaged ; to be more 
exact, it looked like the place where a 42 
cm. shell has recently landed. But the 
clock craze had struck in ; and oblivious 
of everything, in cloistered seclusion be- 
hind the barn I pondered upon Hipp and 
his exasperating agate. 

I pondered long before, in a burst of 
enlightenment, the great truth of Bugdom 
burst upon me — use some other material, 
even if it isn't as good, anything at all 
for a starter. Couldn't I use steel, brass 
even ? it would last long enough to try it 
anyhow. It makes me laugh now, my great 
discovery; but do you know that some- 
times the getting rid of a fixt idea is the 
hardest part of an undertaking? Why, I 
could have used pewter, paper, I guess 
even cheese if you took it near the rind. 

Don't let anyone discourage you, Bugs, by 
specifying costly and unusual materials. 
The inventor's describing his rinktum the 
way it looks after he's got it all babied 
up in its final Easter dress; but just for 
a trial you don't need the platinum, Bake- 
lite, Empire cloth, and "S.C." wire — no, sir, 
you'll find all you really require in the 
good old junk-box as usual. Me, I grew 
so independent finally in the matter of ma- 
terials that I hardly recognized more than 
two kinds — conductors and insulators ! 

So, having got the agate out of my head 
— -"solid agate" I guess my old bean was — 
I used steel for the post and brass for the 
trigger ; and as to durability, let me tell 
you that after nearly twenty years use I 
can't with the naked eye detect any wear. 

Oh, yes, I made the clock, but I had a 
long hunt for something on Hipp's prin- 
ciple in a form which the amateur work- 
shop might turn out. After many trials I 
evolved the form shown in Fig. 4 ; and I 
make you free of my invention, Bugs, hop- 
ing someone will be interested enough to 
make himself an electric clock. There's 
lots of enjoyment in listening to its sedate 
tick-tock as it breaks up infinite time into 
the small units we need to make our good 
or bad use of. Maybe, now that the war 
will debar us from wireless work for a 
while, you'll feel inclined to take up this 



fascinating subject of clocks; and if so, I 
have many valuable "wrinkles" which I 
should be delighted to share with you. 
Only, avoid my experience, and don't make 
a business proposition of it at first. C-U-L, 
O-M. -.- 



NEW RESISTANCE MATERIALS, 

A New York concern is now marketing 
tungsten and molybdenum in sheet, rib- 
bon and plate form. This development 
makes these metals suitable for new uses 
and opens to them a much wider field 
of usefulness than has heretofore existed. 
The tungsten and molybdenum ribbon is 
being made in widths of about Y\ in. 
(6.35 mm.) and in lengths of several 
yards. In this shape the ribbons ought 
to be ideal material for the manufacture 
of heaters of various descriptions and suit- 
able for high temperatures, the manu- 
facturer points out. The United States 
Government has already placed an order 
for plates of these metals for spark gaps 
on wireless outfits to be used on its Mos- 
quito Fleet. 



KINKS FOR THE DRAFTSMAN. 

The first "kink" shown is a new section- 
liner. There are a great number of appli- 
ances on the market for this purpose, but 
the one described will do the same work 
as the most expensive device, its advantage 
being simplicity. 

It consists of a sheet of celluloid cut as 
shown. The parts shown in black are cut 
away with a sharp knife, leaving a kind of 
grid. To use this section-liner place its 
base close to the Tee-square and place the 
pen or pencil into the opening and draw 
a section-line, following the outline of the 
grid. Without moving either Tee-square 
or section-liner, place pen into the next slot 
and so on. 

The two corners "X" and "Y" are cut 
away to the angle of threads used and these 
may come in handy when drawing bolts, 
etc. 

The second "kink" will save those drafts- 
men that are oft repetition work much time 
and trouble. It consists of the following: 
Draw all those bolts, nuts, washers, fit- 
tings, etc., that are used over and over 
again in numerous sizes on a sheet of 
tracing cloth and ink it in. Be sure to 
mark, in the case of nuts and bolt-heads, 
from where you strike the radii; see point 
"M"; point "N" shows the height of the 
bolt head arc. 

As most offices use transparent drawing 




A Celluloid Section Liner for Draftsmen 
and a Scheme for Quickly Drawing Nuts or 
Bolt- Heads of Any Size. 

cloth, the standard sheet can easily be slipt 
under the paper and the outlines traced 
thru. In the case of many hundred bolts, 
etc., required, say in details of bolts for 
pipe lines, etc., the saving of time will be 
several hours and a much neater drawing 
will be the result. 

Contributed by C. A. OLDROYD. 



ii6 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



The Influence of Light upon the Contact Potential of 

Selenium and of Cuprous Oxid 



THE change in resistance of crystal- 
line selenium and other light sensitive 
substances, such as stibnite, cuprous 
oxid, etc., under the action of light and oth- 
er agencies, has been explained on the as- 
sumption that it is due to a liberation of 
conducting electrons from the atoms of the 
material in question.* In other words, the 
change may be considered as due to a 
change in the atom itself. If this expla- 
nation is correct, then other properties of 
these substances, which also depend upon 
inter-atomic forces, should show a varia- 
tion from light to dark. The authors in- 
vestigated the influence of illumination up- 
on the contact potential of selenium and 
of cuprous oxid, since this property is one 
of those mentioned above. 

Using, as a check upon each other, two 
different methods, Figs. 1 and 2 of deter- 
mining contact potentials, it was found that 
a change did take place in both substances 
upon illumination. In the case of selenium, 
this difference amounted to something over 
— 0.1 volt, several specimens being exam- 
ined. The value, in the dark, of the con- 
tact potential, relative to clean copper, was 
about — 0.4 volt, in the light about — 0.5 volt, 
i.e., the selenium surface becomes more 
negative on being illuminated. With cup- 
rous oxid, of which but one specimen has 
been examined thus far, the effect is not 
so great, being about — 0.025 volt. 

In the case of selenium the effect is very 
marked, even when light of very low in- 
tensity was used, as can be seen from the 
curve in Fig. 3, which shows the relation 
between the change in contact potential and 
lamp voltage. Thus, with a lamp voltage 
of 25 volts (normal 110) the change 
amounts to about 0.035 volts, yet at 110 
volts at which the intensity of illumination 
has increased by a factor ©f about 2,000 
over that at 25 volts, the effect is only 3}4 
times as great. 

Until recently the most widely accepted 
theory of the change in resistance of sele- 
nium with a variation of the intensity of 
illumination has been that proposed by Pro- 
fessor A. H. Pfund, of Johns Hopkins Uni- 
versity. According to this theory, the ef- 
fect of light is in the nature of an internal 
photo-electric effect, i.e., the atoms of sele- 
nium expel electrons, the velocity of which 
is too low to allow their escape from the 



By. E. H. KENNARD and E. O. DIETERICH 
Department of Physics (University of Minnesota) 

nated, the concentration of free electrons 
would be increased, and one should expect 
diffusion of these electrons into the darker 
portions, leaving the part illuminated more 
positively charged. The negative sign of 
the change in contact potential, however, at 
once rules out the diffusion hypothesis and 
makes the simple theory mentioned above 
inadequate. An hypothesis which better 
fits the facts is that contained in a theory 
recently proposed by Professor F. C. Brown 
of the Iowa State University, which as- 
sumes that the action of light consists in 
changing the rate of recombination of con- 
ducting electrons with the selenium atoms, 
or, in other words, it decreases the potential 
energy of the electrons in the inter-mole- 
cular spaces. 

POPULAR DISCUSSION ON THE 
PRODUCTION OF HELIUM 
By Mark Fushman. 

In a spectroscopic investigation, Janssen 
and Norman Lockyer observed in the at- 
mospheres of the sun and many fixt stars, 
a bright yellow line which could not be 
associated with that of any known sub- 
stance. To this new substance they gave 
the name "Helium." Helium was discov- 
ered on the earth in 1895 by Ramsay and 




SO 7S 

Lamp l/o/foqe 



Curve Showing Relation Between Light on 
Selenium and the Contact Potential. 

interior, hence they produce increased con- 
ductivity. The true explanation, however, 
does not seem to be as simple as this, for 
on the above theory, in the regions illumi- 

* A more complete discussion of this wort is 
to be found in the Physical Review for January, 
1917. This article prepared for The Electrical 
Experimenter.'" 





< 






AAA/ 




) Se. 


c 




Fig- 2 @ 



Ionization Method of Measuring Contact Po- 
tential. This Method Is Also a Null Method 
as the Diagram Indicates. S Is a Copper 
Strip Coated with Polonium, the a-Particles 
from Which Ionize the Air Above the Sele- 
nium, Se, But Do Not Strike the Selenium 
Surface. G, as in the Other Method, Is a 
Brass Gauze Connected to the Electrometer. 

Travers, who obtained it by heating the 
rare mineral Cleveite. Later on, it was 
found that this element is a companion to 
Argon. Lastly, it was also discovered in 
the atmosphere. 

Helium has an atomic weight of 4.00 and 
is monatomic, i.e., that is — the helium mole- 
cule consists of only one atom. At or- 
dinary temperatures, helium is a colorless 
gas; it boils at about 269°C, and by evap- 
oration at a pressure of 0.15 mm., a tem- 
perature 1.5 above absolute zero was ob- 
tained. 

The fact that this new gaseous element 
occurred in certain minerals was consid- 
ered very remarkable. A new light was 
thrown on this subject by the discovery of 
radioactivity. Radioactive substances are 
known to emit spontaneously electrons, or 
particles, as they are now termed. As 
these particles are emited the substance 
changes into a new and different element ; 
this is known as the disintegration theory 
of radioactivity. In looking for a disin- 
tegration product, the presence of helium 
is noteworthy, for helium is found in min- 
erals containing uranium or thorium. 
Rutherford and Soddy suggested that hel- 
ium might be a product of disintegration. 
Ramsay and Soddy obtained thirty mini- 
grams of radium bromid and dissolved it 
in water. Radium bromid produces hydro- 
gen and oxygen, so these gases were 
drawn off and there remained a small 
bubble of residue gas, which was intro- 



ducd into a vacuum tube and showed the 
characteristic lines of helium. When a 
very old sample of radium bromid was 




Condenser Method for Measuring Quick 
Changes in the Contact Potential. The Elec- 
trometer, E, Can Be Connected by Means of 
Suitable Clips, Either to the Gauze, G, the 
Selenium Plate, Se, or the Copper Plate, C. 
As Shown in the Diagram the Connections 
Are Such That, by Means of the Poten- 
tiometer, P, the Deflection of the Electrom- 
eter Which Occurs When Light Falls on the 
Selenium Plate Thru the Gauze, Can Be 
Made Zero, and the Change in Contact Po- 
tential Determined. Proper Precautions Are 
Taken, of Course, to Secure Proper Electro- 
static Screening. 

used, the residue bubble gave the complete 
spectra of helium. This experiment 
showed that helium was produced by rad- 
ium. Helium is also produced from active 
forms of actinium. This shows also that 
helium ought to be a common product of 
both substances. 

Radium, owing to its property of giv- 
ing forth particles, gives forth certain par- 
ticles which are called alpha particles. In 
old radioactive material there is a large 
collection of helium which goes to prove 
that the alpha particle is connected with 
helium or rather that an alpha particle is 
a helium atom. An estimate of the rate of 
production of helium from radium has 
been made by Ramsay and Soddy. 1 gram 
of radium produces daily 0.499 cu. mm. 
helium gas. 

Investigation seems to show that the 
alpha particles from actinium and thorium 
are also atoms of helium; therefore we 
may regard these elements as compounds 
of helium and some unknown element. It 
appears that helium plays an important 
role in the formation of the radioactive 
elements. It may be that helium, like hy- 
drogen, plays a part as one of the elemen- 
tary elements of which the heavier atoms 
are built. 

It is supposed that at the center or 
rather in the depths of the earth, where 
the pressure is great and the temperature 
high, radioactive elements are being formed 
and the deposits of radio-elements now on 
the earth's surface were thrown up from 
below ages ago. 

CARD INDEXING THE "E.E." 

I have a little stunt which I thought 
might be of interest to other readers, as 
follows : 

I took a small card index that is sold 
for a recipe file and sold for $1.00 any- 
where, and as I read my Electrical Ex- 
perimenter each month, I note on the 
cards all those things that may be of fu- 
ture use to me, in this way: 

Antenna Switch-Exp. Jan., 1917, page 
658: then at any time that I want to make 
anything, I look at the cards and all ar- 
ticles in my stack of magazines are listed 
there, which saves hunting thru a stack of 
several dozen magazines for something you 
have seen, hut cannot find. 

Contributed by F. C. BROWN. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



High Frequency Apparatus and Experiments 



By HUBERT A. McILVAINE 



MANY experimenters either do not 
realize the vastness of the high 
frequency Held, or think that they 
have not money enough to buy 
the necessary apparatus. It is the 
purpose of this article to explain the man- 
ner of constructing a few simple instru- 
ments, and the method of carrying out 
some simple experiments. 

In the first place, a high frequency trans- 
former must be constructed. An Oudin 
coil will be the best for all-around work, 
and it may be made in the following simple 
manner : Procure an ordinary pasteboard 
mailing tube, about 2 l / 2 inches in diameter 
and 10 inches long, and cover it with a thin 
coat of white shellac. While this is still 
wet, wind the tube with fine copper wire, 
spacing the turns far enough apart to en- 
sure proper insulation. (Enough wire may 
be found in an old telephone ringing mag- 
net.) Glue this tube upright to a base and 
fasten three posts on the base. The pri- 
mary coil may be made of 6 turns of No. 14 
copper wire, connected as in the diagram, 
Fig. 1. 

A condenser can be made by coating both 
sides of old photographic plates with tin- 
foil, and placing them in a cigar box, to 
hold them in an upright position. A spark 
gap of most any type will answer. A V/i 
inch spark coil should be used. 

When the above instruments are con- 
structed, they should be connected up as 
shown in diagram, and the apparatus is 
ready. When the spark coil is operated, a 
brush discharge of purple light should ap- 
pear around the free end of the secondary, 
ucoer end of coil, with sparks about 2 or 3 
inches in length. If a piece of metal is 
held in the hand, a very long spark can be 
drawn from the secondary wire, without 
the slightest shock. If, however, the spark 
is drawn directly into the hand, a severe 
sting may result. On the other hand, if a 
pane of glass is held between the secondary 
wire and the hand, a spark may be received 
directly into the hand without pain ; the 
spark, being dispersed or spread out while 
passing over the glass. 

If a person insulated from, the ground 
grasps the free terminal of the secondary, a 
match may be lighted from any part of the 
body. A Geissler tube will light up bright- 
ly, when brought near the body. This is 
also a good way in which to treat heart and 
nervous diseases. If there is any local 
trouble, a grounded metallic object should 
be brought near the point to be treated, thus 
taking out the induced current at this 
point. 

An interesting experiment is to produce 
an artificial Aurora Borealis. This may be 
accomplished with a large electric bulb (a 
100 watt, burned out one will do), covering 
the tip with tin-foil. Insulate the bulb 




Fig. 1, Proper Connections for Small 
"Oudin" High Frequency Coil Excited by a 
Spark Coil or Step-up A. C. Transformer. 

from the ground and fasten the screw end 
to the secondary wire. Place a strong per- 
manent magnet on each side and start the 
coil. A beautiful auroral effect will form 




Wood dowe// p/n 



G/oss feet 



Fig. 2. Manner of Constructing Small "Oudin" Type High Frequency Coil for Carrying on 
a Series of Interesting Experiments. One of These Is the Artificial "Aurora Borealis," 
Which Is Produced with the Aid of an Incandescent Lamp Bulb, Having Its Tip Portion 
Coated with Tinfoil, and Connected as Shown. 



inside the bulb. Also, if there are any 
loose pieces of filament, these will begin to 
revolve rapidly about the inside of the bulb 
and will continue to do. so for some time 
after the current is shut off, and each time 
they touch the glass a shower of sparks will 
fly in all directions. 

A by-product of high tension electrical 
stress in the air is ozone. Ozone is merely 
electrified oxygen. When a high voltage 
discharge takes place in air or pure oxygen 
gas, the atoms of oxygen are "torn apart" 
and exist in what is known as a nascent 
state. In this state each atom combines 
with one other atom, and the chemical af- 
finity of these two atoms is such that, as 
there is nothing with which they can com- 
bine, these atoms pull to themselves and 
combine with a third atom of oxygen. 
Thus it is that a new gas> is formed. This 
gas is much denser than oxygen and is 
many times as active. The smell of ozone 
is very strong and there seems to be a slight 
difference in the smell of ozone produced 
with a static machine and the ozone pro- 
duced with high frequency current. Ozone 
is an excellent "germ killer," as it kills all 
kinds of disease germs on contact. If it is 
administered properly, and in time, it will 
cure consumption. 

The electric stress about the coil is so 
great, that immense quantities of ozone are 
constantly being generated. In order to 



treat diseases obtain a box which is large 
enough to contain the coil and still leave 
enough space (about 4 inches) on each side 
to prevent the coil from "grounding." Run 
the coil wires through the box and leave the 
free end of the secondary about six inches 
long, so as to obtain good radiation sur- 
face. Place a hose in the top of the box 
and another in the lower part of one side. 
Paraffin the box to prevent leakage, and 
put a small window in one side so that the 
coil action may be viewed. Either air or 
pure oxygen is taken in thru the lower 
hose and the ozone is inhaled, or otherwise 
applied from the upper hose. In fumiga- 
tion, treatment of coughs, pneumonia, colds, 
and for many other medical uses, besides 
oxidation of certain materials, bleaching 
flour and cloth, experimenting with its use 
in welding and many other commercial uses, 
ozone is a most valuable agent. 

Taking the high frequency field as a 
whole, it is well worth while for more ex- 
perimenters to work with it. High fre- 
quency current has the properties of both 
static and galvanic electricity, besides many 
properties which neither of the above pos- 
sess. It will pass over ordinary insulators, 
such as glass, almost as easily as low fre- 
quency current will pass thru copper. It 
travels over the surface of a conductor 
and seldom thru it. Its oscillations are 
(Continued on page 154) 



1 18 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



The Problem of Using The Energy in Sunlight 



INFRACTION 
CRATING 
PLANE 



A RESEARCH PROBLEM AND 
OUTLINED SOLUTION. 

SUPPOSE all the electrical energy 
used in the world for power, heat 
and light to be obtained for nothing. 
How the world would be changed. 
Energy in electrical form, of limitless 
amount and absolutely free, is falling over 
a world provided with apparatus and appli- 
ances for the use of electric energy. But 
the world does not use this constant, ex- 
haust.less flood of free energy; it digs coal 
out of the earth and depends on that for its 
power, heat and light. 

The greatest discovery any experimenter 
can seek is the direct utilization of solar 
energy as the source of power for the 
world's work. 

The following out- 
line of experimental 
research may enable 
some so circum- 
stanced that they 
can make the inves- 
tigations, to make 
this discovery. In 
this work I seek to 
obtain energy from 
solar radiation by 
causing it to pro- 
duce ordered accel- 
eration of electrons 
about, and in, a con- 
ductor — electric 
current. 

Problem: — To Ob- 
tain Electrical 
Energy "Directly" 
from Solar Radi- 
ation. 

1°. The solution 
here proposed is 
based on the follow- 
ing principles : 1. 
The solar radiation 
is electro - magnetic. 
2. The flow of en- 
ergy is in the direc- 
tion of propagation, 
sun to earth. 3. The 
periodic action, vi- 
bration, is at right 
angles to the propagation, and is cyclic 
variation of two vector magnitudes, elec- 
tric force and magnetic force. 4. Solar 
radiation produces acceleration in electrons 
in its path that have a component of motion 
in a certain relation to it. 5. Acceleration 
of an electron produces an (opposite) ac- 
celeration of surrounding electrons. 

2°. The experimental solution is rendered 
difficult by the great complexity of the so- 
lar radiation. Take a small area in a plane 
at right angles to the solar beam. At every 
instant there are passing Jhru this waves of 
millions of different lengths and periods, 
and at every instant they are in millions of 
different phases, and the electric and mag- 
netic vectors in these waves at any instant 
are in millions of different directions and 
continually changing at every point. 

3°. A beam of one wave length or period 
approximately may be obtained by the use 
of a prism or a grating, preferably a grat- 
ing. 

4°. A beam with the electric vector con- 
fined to one direction may be obtained by 
the use of a polarizing mirror or a pile of 
plates ; or to two directions, giving elliptic 
resultant by an additional mirror or a 
rhomb. 

5°. A complex beam, a beam of one 
wave length, or a beam of one wave length 
and one direction of electric vector, may be 
concentrated to a small area, circular or 
linear, in which, at any given instant, there 



By Prof. I. Thornton Osmond 

is but one phase in the focus of a lens, 
spherical or cylindrical, all waves (of a 
given length) are in the same phase at any 
instant. 

6°. Two parts of a complex beam, of a 
one wave length beam, or of a one wave 
length and one electric vector beam may be 
made to traverse the same space by the use 
of a biprism or a mirror in such a way that 
the intensity at various places at any in- 
stant has values that vary from zero to 
four times that of the single beam. 

7°. Take a vessel with walls readily tra- 
versed by the solar radiation and that may 
be exhausted to high vacuum if desired, 
and produce in it an abundant supply of 
electrons (as by a filament or wire heated 
by a current ) and bring into this vessel 
electrodes to receive the radiant energy 



EVACUATED TUBE 




Arrangement of Apparatus as Suggested by Mr. S. Cohen, for Use in Determining 
the Most Effective Energy Components in "Sunlight." The Various Rays Are 
Focussed from a Diffraction Grating Into a Vacuum Bulb, and Their Magnitude 
Measured by the Reaction Deflection of an Electro-static Galvanometer Connected 
Across Two Electrodes, Charged As Shown by a High Tension Arc or Other 

Generator. 



treated as in 3, 4, 5, 6, and send it thru an 
external circuit, containing such capacity, 
induction, and resistance as may be re- 
quired, and some form of indicator, as a 
galvanometer, telephone, or wave detector. 
(The vessel, vacuum and ionizer may not 
be necessary; possibly the energy of the 
treated beams can be taken by the elec- 
trodes without these.) 

8°. By the various combinations of ap- 
paratus, in 10-below, using solar radiation, 
produce in the vessel the linear focus, or 
foci, of the different character beams of 3 
and 4 above; or produce within it the space 
variations of intensity of 6 above, with any 
of the kinds of beams named. Try various 
relations of variously formed electrodes 
to the focus, or foci, and to the regions of 
different intensity; with various ionizing 
current, as direct, high frequency alter- 
nating, or spark discharges of coil or con- 
denser, and various inductances, resistances 
and capacities in the external, or receiv- 
ing, circuit — using one or another of the 
indicators named above. 

9°. Apparatus for Proposed Experimen- 
tal Solution. — 1. Lens of sulfur, paraffin or 
synthetic resin, cylindrical, 27 cm., chord, 
40 cm. long, 50 cm. focal length ; two oth- 
ers, each 22 cm. chord, 40 cm. long, 50 cm. 
focal length. 2. Grating, plane, 34 ele- 
ments, a+b=1.2 cm., 40x41 cm. inside of 
frame. Also a curved, cylindrical grating, 
100 cm. radius, 32 elements, a4-b=1.5 cm. 3. 



Fresncl Mirrors, one 40x40 cm., the other 
40x60 cm. ; the latter serving for a Lloyd 
single mirror, if wanted. 4. Biprism, sul- 
fur, 25 cm. wide, 40 cm. long; small an- 
gles 7°, large angle 166°. 5. Polarizers, re- 
flecting metal plate, pile of plates, glass or 
sulfur; fine grating; Fresnel rhomb. 6. 
The transferring, or receiving, apparatus 
described in 7 above (which may not be 
necessary). 7. Accessory apparatus, as ca- 
pacity, resistance, inductance, and indicat- 
ing instruments. 

Wherever wave length enters into the 
design of these pieces of apparatus it is 
taken as from 0.6cm., to 1.2cm., as being 
near the lower limit of waves well above 
the longest heat waves, i.e., waves produc- 
ing molecular motion. Greater wave 
lengths, with corresponding changes in de- 
sign may be found 
to give better results. 

10°. Apparatus 
Combined for Ex- 
periments, giving 
various kinds of 
radiation beams. — 1. 
Grating and Lens, or 
Lenses ; or Lens and 
Curved Grating. 2. 
Grating and Polar- 
izer. 3. Grating, 
Polarizer and Lens, 
or Lenses. 4. Grat- 
ing, Polarizer and 
Ellipsizer. 5. Grat- 
ing, Polarizer, Ellip- 
sizer and Lens. 6. 
Lens and Biprism or 
Lens and Mirror. 7. 
Grating, Lens and 
Biprism and Mirror. 
8. Grating, Polar- 
izer, Lens and Bi- 
prism. 

For this work it 
would be desirable, 
perhaps necessary, 
to have a complete- 
ly metal (iron) in- 
closed container of 
the instruments. If 
a room of this kind 
is not available, an 
iron case 2.4 meter (m.) long 0.5m. wide, 
0.8m. high will contain any of the com- 
binations of apparatus given above and the 
transferring, or receiving, apparatus. The 
mounting of the combination of apparatus 
should permit following the sun or direct- 
ing to any point within 90° of it. 

An electrolytic process of deoxidation 
has been patented in the United States by 
Pascal Marino of London. The object to 
be treated is made the cathode in an elec- 
trolyte containing phosphoric acid. In ad- 
dition to its normal function of carrying 
the current, this acid acts as a solvent upon 
rust without attacking the steel or iron 
body beneath. It is in this last detail that 
its chief availability lies, since nitric, sul- 
furic or hydrochloric acids would not dis- 
play such moderation. Finally, the phos- 
phoric acid is beneficial in preventing sub- 
sequent further rusting. 

The electrolyte is made by adding ten 
parts of phosphoric acid to ninety parts of 
water, or by adding 10% o the acid to a 
10% solution of sodium phosfate. 

Due to the advent of the war, we are 
particularly desirous of obtaining manu- 
scripts describing original and practical 
"Electrical Experiments." We shall 
continue to publish Radio articles, but 
what we need is snappy "Electrical" 
articles. Be on guard for the enemy — 
Repetition! 



June, 1917 



THE ELECTRICAL EXPERIMENTER 




This department will award the following monthly prizes: First Prize, $3.00; Second Prize, $2.00; Third Prize, $1.00. 

The purpose of this department is to stimulate experimenters towards accomplishing new things with old apparatus or old material, 
and for the most useful, practical and original idea submitted to the Editors of this department, a monthly series of prizes will be 
awarded. For the best idea submitted a prize of $3.00 is awarded; for the second best idea a $2.00 prize, and for the third best prize of 
$1.00. The article need not be very elaborate, and rough sketches are sufficient. We will make the mechanical drawings. Use only one 
side of sheet. Make sketches on separate sheets. 



FIRST PRIZE, $3.00 

A NOVEL ELECTRIC CHIME. 

The accompanying illustration shows an 
electric chime which I have used in place 
of an ordinary vibrating bell. 




When the First Gong Strikes, Its Dependent 
Armature Closes the Circuit Thru the Sec- 
ond Gong Magnet "E", Etc. 

The bell armature should be lengthened 
and two contact points soldered to the end. 
When a button is pushed the armature of 
bell C is drawn over, striking the bell once. 
The lower contact then strikes N and 
throws bell E in circuit. The armatures 
stay over against the magnet as each suc- 
cessive bell is put in circuit, thus keep- 
ing the circuit thru lower contacts complete. 
When bell F is rung, the battery circuit 
is broken, and all the armatures fly back. 
Thus the operation is repeated. The gongs 
should have different tones to give a pleas- 
. ing chime eff ect, and as many bells can be 
used as desired. 
Contributed by A. G. CORKRAN. 

"HARD RUBBER" BASES FROM 
"VICTROLA RECORDS." 

Wishing to make a detector and not hav- 
ing a suitable base I procured a piece of oak 
(any wood will do) and an old phonograph 
record. I cut the wood and record to the 
desired size. I then put a thin layer of 
shellac on the wood and prest the piece of 
record on it, and left it for a few hours. 
When it was dry I sandpapered the edges 
and polished the composition rubber. 



Phonograph record 
covering 




Do You Want a Hard-Rubber Instrument 
Base? Just Cut a Piece of a "Victrola" 
Record and Glue It to a Wooden Sub- Base. 

If the above directions are followed very 
neat bases can be made by the amateur. If 
the hole in the record does not allow a large 
base to be made, cut a circular piece of 
the composition rubber and plug it up. 

Use records that have one side blank. 

Contributed by HYMAN R. WALLIX. 



SECOND PRIZE, $2.00 

SIMPLE AUTOMATIC CIRCUIT 
BREAKER. 

The circuit breaker described below is 
giving efficient service on the switchboard 
in my laboratory. The pieces A, B, C and 
D are brass strips ; E, is a soft iron screw 
with two nuts to fasten it to the trigger 

C. F is an electro-magnet wound with 
No. 12 silk insulated magnet wire. The 
core of this magnet was obtained from an 
electric bell. The spring G, and the ad- 
justing screw are used to regulate the in- 
strument. The connections are as shown. 
The breaker is used on 110 volt A.C. or 

D. C. lighting circuit. When the contact 
A touches the contact B, it is held there 
by the trigger C. The magnet F is always 
magnetized to a certain extent but an 
overload or short-circuit causes the mag- 
net to attract the armature C, releasing the 
contact A, which breaks the circuit. It 
is to be manually reset. 

Contributed by ALGIE RIGGS. 



THIRD PRIZE, $1.00 




To load 



To line 



© 



In this Circuit- Breaker the Armature 
Normally Holds the Spring "A" Down; an 
Overload Causes the Magnet to Attract 
"E", Thus Opening the Circuit. 



WALNUT STAIN. 

The following stain is excellently adapted 
to the finishing of wireless and electrical 
cabinets and instruments, and for various 
other wooden articles which is desired to 
have a uniform coloring or finish. 

Prepare a solution of 6 ounces of a 
solution of potassium permanganate, and 6 
ounces of sulfate of magnesia in 2 quarts 
of hot water. The solution is applied with 
a brush and the application should be re- 
peated. In contact with wood the potas- 
sium permanganate decomposes, and a last- 
ing walnut color results. If small pieces 
of wood are to be thus stained, a very di- 
lute bath is prepared according to the 
above description, then the wooden pieces 
are immersed and left in the solution for 
from 1 to 5 minutes, according to whether 
a lighter or darker color is desired. 

Contributed by 

ALBERT W. WILSDON. 



ELECTRIC FURNACE MADE FROM 
PLUMBAGO CRUCIBLE. 

An interesting and practical electrical 
furnace can be made of a plumbago crucible 
(used by jewelers) and two gas carbons. 
One of the carbons can be inserted in a 
hole drilled about 1^4" from the bottom 
of the crucible, and the other held in a 
clamp. But some method must be devised 



THE SIMPLEST FLASHLIGHT. 

Here's the simplest flashlight one can 
make : A flashlight bulb, A, and battery, 




Hats Off to Mr. Peterson — Inventor of the 
"Simplest" Electric Flashlight. Can You 
Beat It? 

and in some cases a strip of brass, B, sold- 
ered to the small battery terminal if it is 
not long enough. The lamp bulb is care- 
fully soldered to the longer terminal strip. 
The lamp is lighted by holding battery in 
hand and pressing with thumb on strip B. 
A reflector (a nickel-plated thimble will do) 
mav be fixt to the bulb if desired. 

Contributed by ERWIX PETERSON. 

to start the arc — that is, to bring the car- 
bons together and draw them apart. A 
simple way is to place the crucible on a 
long board, to be used as a lever, fas- 
tened to the base by a hinge of leather. 
An interesting experiment can be performed 
by filling the crucible with ground glass 
up to the lower carbon rod. An arc may 
be started between the two gas carbons, 
and this will heat the glass to redness. 
An arc will then be formed with the car- 
bon rod and the hot glass as electrodes. 



ruses 



Plumbago 
Crucible \ 



HS1 



110 Volts A.C 




A Simple "Arc" Furnace Made From Two 
Carbon Rods and a Plumbago Crucible. 

The eyes should always be shielded from 
the intense light of the arc by dark glasses. 
Contributed by TOM RIEBE. 




Can you send and receive at the 



AMATEURS ! 
ATTENTION!! 



Now that we are for the time 
being, deprived of using our 
Radio outfits, it behooves us to 
become proficient in learning 
the Wireless Codes. Operators 
who know the Code are, and 
will be, in ever rising demand. 
The army and navy need thou- 
sands of operators right now. 
required speed, when your country 



Can you qualify? 

calls you? 

The Radiotone Codegraph is positively the only instrument made that will send such 
an unbelievably close imitation of a high pitch Radio Station, that it has baffled experts. 
The outfit replaces the old-fashioned learner's outfit, consisting of key and sounder. The 
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special loud talking receiver with horn, and a key all mounted on a base. Operated on 
one or two dry cells, the phone will emit the characteristic high pitch sound, which while 
not harsh, is heard all over the room. With little trouble you can learn the code correctly 
in 30 days — - — 7 

AND THAT IS NOT ALL: 

Connect two of these outfits together for intercommunication work and you and your 
friend five or fifteen blocks distant can converse over a NO. 36 WIRE, so fine that no one 
will see it. Or you can use instead of the wire, a metallic fence and the ground. Or you 
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Selenium Cells 

Everybody has read about 
the experiments of telepho- 
tography (sending photo- 
graphs over a wire hundreds 
of miles) made by Professor 
Korn and others. It is also 
known that if the problem of 
tele-vision is ever solved, the 
selenium cell will play an im- 
portant role. At present we 
are the only concern in the 
United States selling these 
cells. They are the most sen- 
sitive ones made. 

Better send for a cell to- 
day and try making an elec- 
tric dog that will follow a 
lamp, or an electric burglar 
alarm. It's very instructive 
and great fun. (See Novem- 
ber, 1916, issue "Electrical 
Experimenter.") 
No. FX5I7 Selenium Cell, 

Shipping Wght., 4 oz. 

$6.00 

IMMEDIATE SHIPMENTS 




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Flag in button-hole of your 
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every time you press the 
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button-hole flashes up with 
a beautiful color effect. 



Illuminated flag, cord and plug (to <t £(\ 

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IMMEDIATE SHIPMENTS 




ELECTRO" TESLA COILS 



This photograph shows a seven (7) inch spark. 

Tesla Coil, made by us in our shops for a well-known institution. 
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No. HK 1800 



The "Electro" Radiotone 

HIGH FREQUENCY SILENT TEST BUZZER 

The RADIOTONE is NOT a mere test buzzer, 
it is infinitely more. Mr. H. Gernsback who de- 
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Yes, the RADIOTONE is SILENT. In fact, 
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You will be astounded at the wonderfully clear, 
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With the radiotone, a key and one dry cell and 
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Radiotone as described each ^.90 

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The "Electro" Rheostat- Regulator 

(Porcelain Base) 

This illustration represents our little current 
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OF PORCELAIN, metal and hard rubber. 

The resistance of our Rheostat is 10 ohms, the 
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"Electro" Pony Receiver 



Our Pony receiver is 
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polished. Powerful per- 
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soft iron core, fibre coil 
heads, very thin dia- 
phragm, brass posts in- 
side. Hanger can be un- 
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will then fit our No. 
AX8077 headbands. 

SOME USES. — For 
all telephone work. 
Also for making the 
small testing outfits for repair men in cir- 
cuit with only one dry cell or flashlight bat- 
tery. When connected in parallel with your 
house telephone receiver, you have a double 
receiver, an invaluable acquisition to those 
who phone in noisy places or to people hard 
of hearing. It can also be used for wireless 
though its low resistance won't permit of 
such good results as a higher resistance 
phone. 

This receiver is single pole; 2 1 4xl% inches; wgt. 
4 oz. : resistance, 75 ohms. IF TWO OF THESE 
RECEIVERS ARE USED, IT IS POSSIBLE TO 
SPEAK AT A DISTANCE OF 150 FEET WITH- 
OUT USING BATTERIES. ONE WIRE BEING 
SCFFICIHXT IF (JROt'.M) IS I'SED. <t-{\ (fl 
No. EKI024 Pony Receiver, 75 ohms «pU.OU 

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Each post is furnished with a % in. machine screw and washer (not shown in illustrations). 
Engravings are full size. 

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AMATEURS ! 
ATTENTION!! 



Now that we are for the time 
being, deprived of using our 
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Selenium Cells 

Everybody linn read a hunt 
tin- experiments nf tclejflio- 
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,.f inll.-s) made Liv I'rof.-ss.ir 
Korn and others. It Is also 
It the problc 



i Is 



It's 



in; 



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her, 191H, Issue "Electrical 
Experimenter.") 
No. FX5I7 Selenium Cell. 
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sells for S40.00. ' 



Parents: 

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SOME USES. — P 
all telephone work. u. EK 
Also for making the 
sini.ll testlnc ..milts f..r repair men in cir- 
cuit with only .me drv .-,.■11 ..r flashlight bat- 
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house telephone receiver, v.ui have a double 
receiver, an ln\ ..lu.ii.l.- a.-.|uisltlon to those 
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'The Livest Catalog in America' 



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122 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



A NOISELESS "ALARM" CLOCK. 
By K. M. Coggeshall. 

Have you ever stopt to wonder what 
your friend in the next room thinks when 
your discordant alarm clock rings each 
morning? Have you ever wisht you had 




Did You Ever Hear of a "Silent" Alarm C 
Here's One. It Awakens You by Flashing 
Light on Your Face. Try It. 

some method of waking yourself without 
disturbing your neighbors? Perhaps you 
may arise at five-thirty in the morning while 
the rest of the household do not find 
the necessity of opening their eyes un- 
til six-thirty. Perhaps some one may be 
ill and you wish to awake during the night 
to give him medicine, and yet do not like to 
disturb anyone else who may be asleep. 
Again you may be looking forward to a 
before-dawn start on a fishing expedition 
but out of respect to others you dislike to 
resort to the alarm clock to awaken you. 

To overcome these objections to the or- 
dinary alarm clock, the following apparatus 
was designed to awaken one sleeper with- 
out disturbing the rest of the household. 

A box-like, wooden sub-base was built 
as shown in the sketch. In its face a round 
hole was cut and into this was fitted an or- 
dinary bicycle spot light. A single pole, 
single throw knife switch was screwed to 
the upper inside surface of the sub-base. 
The lamp was then connected, thru the 
switch, to a battery of sufficient capacity to 
utilize its full candle-power. If the sub- 
base is made large enough the battery may 
be enclosed and the entire outfit made com- 
pact and portable. 

The bell, as well as the striker, was re- 
moved from an alarm clock. A thread 
spool was attached to the alarm winding 
key to serve as a drum on which the cord 
to operate the switch was to wind. This 
switching device was very simple. A strong 
cord was attached to the handle of the 
knife switch, brought up thru a hole in the 
base and attached to the spool on the wind- 
ing key. 

The mechanical operation of this device 
can well be imagined. The apparatus is set 
on the mantel or dresser in the bedroom. 



rived, the alarm mechanism operates, turn- 
ing the drum, thus winding in the cord, 
which in turn closes the switch and lights 
the lamp. All this will be accomplished 
noiselessly. No one can sleep with a bright 
beam of light suddenly directed onto the 
face. Furthermore, it is im- 
possible to snatch a few cat- 
naps before getting up with 
this light in the eyes. It is 
therefore imperative that the 
awakened person arise and 
open the controlling switch — 
and once out of bed there is 
little danger of dropping off to 
sleep again. 

ELECTRIC LIGHT FOR 
GUN SIGHTS AT NIGHT. 

As every hunter knows, it is 
extremely difficult to aim cor- 
rectly at night, even tho the 
lock? — Well, game can be seen, for the sim- 
a Beam of pl e reason that the gun sights 
on the barrel cannot be ac- 
curately viewed. 

The accompanying illustration shows how 
a small, frosted, flashlight bulb may be 
placed just behind the forward sight, with 
a metallic shield over it, so as not to throw 
a glare in the gunner's eyes. It is a simple 
matter to bore a hole in the wooden stock 
of the gun with an ordinary carpenter's 
brace and bit, in which to mount a cell or 
two from a flashlight battery, the size of 
these individual cells being about l-54"x7/16" 
in diameter. Also the cells may be placed in 
a brass or fibre tube secured under the 



A 'I arm trey 
w/fi spool 
drttm afldttied 




Stno/I spofl/ghf sue/? as 
used on D/cc/c/e 



dactrofspof 
//g/tf @ 



How an Ordinary Alarm Clock Is Rigged Up 
So as to Close the Lamp Circuit of the "Si- 
lent Alarm." 

The spot light is then so adjusted that the 
full power of the light ray will concentrate 
on the face of the sleeper. The alarm 
should be wound and adjusted as usual. 
When the predetermined hour has ar- 




feolomp 



JjteQ Grounded 



A Tiny Electric Light Fixt Just Back of the 
Forward Sight Proves a Boon to the Hunter 
at Night. 

fore-arm section of the gun frame. A 
switch, of unobtrusive proportions, will 
serve to light the lamp bulb when wanted. 

H. G. 



GOOD INK FORMULAE. 

These two formulae obtained thru orig- 
inal experiments, have been found to pro- 
duce excellent inks. The ingredients are 
easily obtained and at little expense. Rain 
water may be used in place of distilled 
water thus removing the need of having 
any chemical apparatus. The resulting inks 
are each of a beautiful color, make a per- 
manent record, flow easily, and do not 
corrode the pens. The blue ink can be 
used successfully and safely in the most 
delicate of fountain pens. 

Blue Ink: Dissolve one ounce of soluble 
Prussian blue in one quart of cold dis- 
tilled (rain) water. Add to this solution, 
5 grams of oxalic acid. Then filter the 
solution thru filter or blotting paper. 

Black Ink: Dissolve one ounce of ex- 
tract of logwood in one quart of boiling 
water. When cold, add one-fourth ounce 
of potassium bichromate and one gram of 
sodium carbonate. The addition of one- 
fourth ounce of prussian blue improves the 
solution. This ink will cost about 5 cents. 

Contributed by 

CLARENCE S. LEVINE. 



STATIC EXPERIMENTS WITH 
LAMP BULB. 

Materials needed — 1 or more burned-out 
electric light bulbs. 



Experiment — Take the bulb and hold 
it near a rapidly moving belt, connected 
with machinery which is not grounded. 
Hold the brass end of the bulb close to the 




Hold an Incandescent Lamp Bulb Near a 
Rapidly Moving Belt — Usually Sufficient 
Static Electricity Will Pass to Charge the 
Lamp as a Condenser. It Will Give Power- 
ful Shocks. 

belt and sparks will usually jump from the 
belt to the brass cap. 

Charge in this manner for about five min- 
utes, then take it away. Offer it to some- 
one, holding the bulb by the glass end al- 
ways. When the person goes to touch the 
brass end a nice hot spark will jump to 
him, giving a considerable shock. 

Contributed by R. G. DEVANEY. 

KNICK-KNACKS FOR 
"RADIO-BUGS." 

By placing one of the E. I. Co.'s load- 
ing coils against the end of a small loose 
coupler, I have been able to catch stations, 
using up to 6,000 meters, this being done 
without additional inductance in the sec- 
ondary, built for only 800 meters. 

Most loose couplers have the primary 
tube placed in grooves cut in the heads and 
by turning it, a new surface is obtained 
for the slider. Clean the path of the 
slider occasionally with a rubber pencil or 
ink eraser. 

Use Solderall on the next loose coupler 
you build and you will use no other. 

Contributed by ASA S. KELLER. 



AUTOMATIC LIGHT SWITCH FOR 
CLOSETS. 

Herewith is a drawing of a little device 
I made from scrap materials and which 
has proved very efficient. 

It is intended to automatically close an 
electrical circuit on opening the door of 
a dark closet or unlighted room, and by 




( 9rush i 




TS7 T -55 *^ 

Support 
Brass rod 



Spring under, 
tension irnen aoor 
ts c/osed 
lubing soldered to, - ' 
support -~ 

-lamp 




A Reliable Automatic Switch for Closet 
Light. When Door Opens the Switch Rod Is 
Moved Forward by the Spiral Spring as Be- 
comes Evident, and Vice-versa. 

means of a small battery and lamp illum- 
inate the interior. 

As the illustration shows, the materials 
and construction are exceedingly simple. 

Contributed by H. W. WALTER. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 

Experimental Chemistry 



23 



ACIDS, BASES AND SALTS. 

(Continued) 
S stated in the previous installment, 
the basicity of acids are determined 
by the number of hydrogen atoms 
[replaceable by a metal] in its 
molecule. Thus : Mono-basic acids 
contain one hydrogen atom, as Hydro- 



K 




It Is Always Best to Stir Solutions with a 
Glass Rod. Have a Clean Vessel for Each 
Acid if You Would Achieve Satisfactory 
Results. 

chloric acid [HQ], from which only one 
replacement is possible. Di-basic acids 
contain two hydrogen atoms, as, Sulfuric 
acid [H2SO4], from which two replace- 
ments are possible. Tri-basic acids contain 
three hydrogen atoms, as Phosphoric acid 
[H3PO-1], from which three replacements 
are possible. Tetra-basic acids contain four 
hydrogen atoms, as, Normal Silicic acid 
[HiSiOi]. [Note: Normal Silicic acid 
readily parts with half of its water, leaving 
H:Si03, also called Silicic Acid], from 
which four replacements are possible. 
Penta-basic acids contain five hydrogen 
atoms, as Periodic acid [HJOs], from 
which five replacements are possible. 

The higher the basicity of the acid the 
greater the variety of salts it can yield. 

If we take the base Potassium Hydroxid 
to illustrate the replacement of the hydro- 
gen of the acids, we find that Nitric acid 
or Hydrochloric acid can form but one 
salt with Potassium Hydroxid, the reac- 
tions being: — 

KOH + HNO; 
Potassium 
Hydroxid 

and 

KOH 4- HC1 = KC1 4- 
Potassium Hydrochloric Potassium 
Hydroxid Acid Chlorid 

Other acids have the power to form two 
or more salts with the same base. 

If only half the quantity of base that is 
required to neutralize the acid is added, 
half the acid remains unchanged, and on 
evaporating the solution, the excess acid 
will pass off. If only half the quantity of 
acid that is required to neutralize the base 
is added, half the base will remain un- 
changed. Sulfuric acid [H 2 S0 4 ] has been 
found to have the power to form two salts 
with Potassium Hydroxid [KOH], in one 
of which there is twice the amount of the 
metal as in the other. The reactions being : 

KOH 4. H2SO4 = KHS0 4 4- H 2 
Potassium 
[acid] Sulfate 



= KNO3 4- 
Potassium 
Nitric Acid Nitrat 



H.O 
Water 



H 2 
Water 



Water 



4- H„0 
Water 



Potassium Sulfuric 
Hydroxid Acid 

and again : — 

2K0H + H 2 SOi = K,S0 4 
Potassium Sulfuric Potassium 
Hydroxid . Acid Sulfate 

If to a certain quantity of Sulfuric acid 
only half the quantity of Potassium Hy- 
droxid that is required to neutralize it is 
added, the first reaction takes place ; but 
if twice as much Potassium Hydroxid is 



By ALBERT W. WILSDON 
Thirteenth Lesson 

used, the second takes place. An acid of 
this kind can, further, form one salt with 
two bases, in which one metal is sub- 
stituted for one of the hydrogen atoms of 
the acid and a second metal for the other. 

As aforementioned, in the molecule of 
Hydrochloric acid [HQ] as in Nitric acid 
[HNO.i], there is but one atom of hydro- 
gen. If, therefore, the act of neutraliza- 
tion takes place in each molecule it is com- 
plete, and the salt is known as a neutral or 
normal salt. In Sulfuric acid [H 2 SO ( ] 
there are two atoms of hydrogen in each 
molecule, and either one or both of these 
atoms may be replaced. If only one is re- 
placed a salt having the general formula, 
MHSO4, is obtained. This is still an acid, 
while it is also partly a salt. This is known 
as an Acid Salt. 

It may be difficult for some readers to 
associate the names Monobasic, Dibasic, 
Tribasic, Tetrabasic, etc., with the basicity 
of the acids, but as these names represent 




Method of Pouring Small Quantities of Acid 
onto a Glass Rod so That They Drop into a 
Beaker or Other Dish Easily. 

the number of hydrogen atoms in the mole- 
cule, it may be well to memorize the fol- 
lowing : 



tvoporaf/ng 
d/sh \ 



Jsbesfos or 
wire gauze 




large r/ng 
■'support 



f/g 67 



Correct Manner in Which to Place "Evap- 
orating Dish," Wire Gauze and Bunsen 
Burner. 

The prefix Mono — means one 
Di— " two 

" Tri — " three 

Tetra — four 
Penta — five 
Thus, when speaking on monobasic acids, 
by remembering that mono — means one, 
and when associated with the basicity of 
an acid, mono — meaning one, and the 
basicity being the number of hydrogen 
atoms, we can thus see that monobasic 
means one hydrogen atom. 

EXPERIMENT NO. 54— 

Have two small-lipt beakers, or two test 
tubes, one of which will contain 10 cc. 
of a solution of Sodium Hydroxid [NaOH] 
and the other an equal quantity of Hydro- 
chloric acid [HQ]. Pour 5 cc. of the 



Sodium Hydroxid solution in an evaporat- 
ing dish, and immerse in it a piece of blue 
litmus paper, allowing it to remain in the 
solution. Pour small quantities of Hydro- 
chloric acid from the beaker onto a glass 
rod, allowing it to drop into the evaporat- 
ing dish, in the manner shown by Fig. 66, 
stirring the mixture. 

It will be noticed that the litmus paper 
will probably turn red, owing to the fact 
that the solution has too much acid con- 
tained in it. If such is the case, add a 
little more Sodium Hydroxid, by allow- 
ing to drop from a stirring rod in the 
same manner as described for the acid. If 
too much of the Hydroxid is added the 
litmus paper might again turn to a blue 
color, and if this happens, add a little more 
of the acid, drop by drop, till the liquid 
becomes neutral to the litmus paper. It 
may be necessary to keep adding either the 
Acid or the Hydroxid. Introduce another 
piece of red litmus when you think the 
solution is neutral, and if it is unaffected, 
immerse another piece of blue litmus paper 
in it, and then if the solution does not 
affect either the red or blue paper it is 
neutral. If the solution is not clear after 
it has been neutralized, filter it, and throw 
away all but about 15 cc. of it. 

Place the 15 cc. of the solution obtained 
into an evaporating dish, and place on 
either a piece of line meshed iron gauze 
or a piece of asbestos pad, as shown in 
Fig. 67. Apply a light to the Bunsen 
burner under the evaporating dish, and al- 
low the liquid to evaporate [boil] till a 
white solid is formed, or in other words 
till all the water has been driven from 
the original solution. 

The equation of the reaction which took 
place between the Sodium Hydroxid and 
the Hydrochloric acid when neutralized 
was : — 

NaOH 4. HC1 = NaCl -!- H = 

Sodium Hydrochloric Sodium Water 
Hydroxid Acid Chlorid 

We perceive from this equation, that the 
hydrochloric acid no longer is contained 
in the solution, and that the Sodium [Na] 
of the base exchanged, or replaced the 
hydrogen of the acid, forming a salt and 
water. 

EXPERIMENT NO. 55— 

In the same manner as described in the 




If Two or More Liquids Which Have Differ- 
ent Densities and Will Not Mix Are Poured 
into a Jar, They Will Come to Rest in the 
Order of Their Densities, with the Surfaces 
of Each Separating . Them Horizontally. 
Mercury, Water, Oil and Alcohol, When 
Poured in a Test Tube, Will Come to Rest 
in the Order Named. 

preceding experiment, prepare a solution 
of both Potassium Hydroxid and Hydra- 
te C ontinued on Page 127) 



THE ELECTRICAL EXPERIMENTER June, 1917 



124 




Under this heading- we _ will publish every 
month useful information in Mechanics, Elec- 
tricity and Chemistry. We shall be pleased, of 
course, to have our readers send us any recipes, 
formulas, wrinkles, new ideas, etc., useful to the 
experimenter, which will be duly paid for, upon 
publication, if acceptable. 



FREEZING MIXTURES. 

When ice or snow are not to be had and 
for those of us who do not have an up-to- 
date laboratory that is provided with 
agencies of cooling power, I am sure the 
following mixtures will prove most con- 
venient. 

1. Nitrat of ammonia, carbonat of soda 
and water, equal parts by weight ; the ther- 
mometer sinks 57°. 

2. Phosfate of soda, 9 parts ; nitrat of 
ammonia, 6 parts; dilute nitric acid (acid 
1 part, water 2 parts), 4 parts. Reduces 
the temperature from 50° to 21°. 

3. Sal-ammoniac, 5 parts; nitrat of pot- 
ash, 5 parts; sulfate of soda, 8 parts; 
water, 16 parts. Reduces the temperature 
46° or from 70° to 24°. This latter is very 
cheap and easily procured. 

If you have ice and wish to reduce the 
temperature still further, use the follow- 
ing : 

1. Finely pounded ice, 2 parts ; salt, 1 
part. This is a very common recipe. 

2. Finely pounded ice, 2 parts ; crystal- 
lized chlorid of calcium, 3 parts. 

3. Finely pounded ice, 7 parts ; dilute 
nitric acid, 4 parts. This reduces the tem- 
perature from 32° to 30°. The tempera- 
tures given are Fahrenheit. The materials 
should be kept as cool as possible. 

Contributed by MINARD ROTE. 



SOLUTION FOR MAKING WORK 
TABLE IMPERVIOUS TO ACID 
AND ALKALI SOLUTIONS. 

Doubtless, many experimenters, especially 
those working with the various chemical 
reagents, desire some coating for the work 
table that is impervious to both acid and 
alkali solutions. The writer has used the 
following method in his laboratory with 
decided success, and heartily recommends 
it to those who desire a similar formula. 

Two solutions are to be made : 

Solution 1. Iron sulfate, 4 parts; copper 
sulfate, 4 parts; potassium permanganate, 
8 parts ; water, 100 parts. 

Solution 2. Aniline, 12 parts ; hydro- 
chloric acid, 18 parts ; water, 100 parts, or 
aniline hydrochlorat, 15 parts; water, 100 
parts. 

Apply two coats of solution No. 1, while 
hot, applying the second coat as soon as the 
first has dried. After solution No. 1 has 
dried, the excess of solution which has 
dried upon the surface of the wood is 
thoroly rubbed off before the application 
of solution No. 2. 

Next, two coats of solution No. 2 are 
applied, and the wood permitted to dry 
thoroly. The black color does not appear 
at once, but requires a few hours before 
turning to a rich ebony-black color. Later 
a coat of raw linseed oil is to be applied 
with a cloth. 



RECIPES FOR KILLING FLIES. 

The United States Government makes 
the following suggestion for the destruc- 
tion of house flies : Formaldehyde and 
sodium salicylate are the two best fly poi- 
sons. Both are superior to arsenic. They 
have their advantages for household use. 
They are not a poison to children ; they are 
convenient to handle ; their dilutions are 
simple, and they attract the flies. 

Preparation of Solutions : — A formalde- 
hyde solution of approximately the cor- 
rect strength may be made by adding 3 
teaspoon fuls of the concentrated formalde- 
hyde solution, commercially known as for- 
malin, to a pint of water. Similarly, the 
proper concentration of sodium salicylate 
may be obtained by dissolving 3 teaspoon- 
fuls of the pure chemical (a powder) to 
a pint of water. 

A container such as shown below has 
been found convenient for automatically 
keeping the solution always available for 
flies to drink. An ordinary, thin-walled 
drinking glass is filled or partially filled 
with the solution. A saucer, or small plate, 
in which is placed a piece of white blot- 
ting paper cut the size of the dish, is put 
bottom up over the glass. The whole is 
then quickly inverted, a match placed under 
the edge of the glass, and the container is 




Now That the "Fly Season" Is With Us, the 
Non-Poisonous (to Humans) Wet Blotter Fly 
Annihilator Shown, Which Is Recommended 
by the U. S. Government, Should Prove 
Particularly Valuable. 



ready for use. As the solution dries out 
of the saucer the liquid seal at the edge of 
the glass is broken and more liquid flows 
into the lower receptacle. Thus the paper 
is always kept moist. 

Other Simple Preventives :— Any odor 
pleasing to man is offensive to the fly and 
vice versa, and will drive them away. 

Take five cents' worth of oil of lavender, 
mix it with the same quantity of water, 
put it in a common glass atomizer and 
spray it around the rooms where flies are. 
In the dining-room spray it lavishly even 
on the table linen. The odor is very dis- 
agreeable to flies but refreshing to most 
people. 

Geranium, mignonette, heliotrope and 
white clover are offensive to flies. They 
especially dislike the odor of honeysuckle 
and hop blossoms. 

According to a French scientist, flies have 
intense hatred for the color blue. Rooms 
decorated in blue will help to keep out the 
flies. 

Mix together one tablespoonful of cream, 
one of ground black pepper and one of 
brown sugar. This mixture is poisonous 



The tables are cleaned very easily by 
washing with water or suds after any work 
is finished, and the application of another 
coat of oil puts them in excellent order 
for another experiment. 

Contributed by 

ALBERT W. WILSDON. 



to flies. Put in a saucer, darken the room 
except one window and in that set the 
saucer. 

To clear the house of flies, burn pyre- 
thrum powder. This stupefies the flies, but 
they must be SWEPT UP and BURNED. 

Reccipcs for Stables, Barns and Out-of- 
doors: — Borax is especially valuable around 
farms and out-of-doors. One pound of 
borax to twelve bushels of manure will 
be found desirable as a poison without in- 
juring its manurial qualities on farm stock. 
Scatter the borax over the manure and 
sprinkle with water. 

Lye, chlorid of lime, or copperas (sul- 
fate of iron) dissolved in water, crude car- 
bolic acid, or any kind of disinfectant may 
be used in vaults. 



HEKTOGRAPHS. 

What are they, do you ask? The Cen- 
tury Dictionary defines it as follows : "A 
copying process in which the writing or 
drawing to be copied is made on smooth 
paper in aniline ink, and is then prest 
upon a slab coated with gelatin, to which a 
part of the ink is thus transferred, and 
from which a number of duplicate impres- 
sions can be made ; also, the special ap- 
pliances, collectively, by means of which 
this is done." The chance, however, is 
that you do not want any definition, but 
might like some directions for simplifying 
the process, which some teachers and stu- 
dents who want a number of copies of text 
oi drawing, are using successfully. Agree- 
able to this contingency, we have : 

Receipt No. 1. — Soak an ounce of fish 
glue in cold water. Drain off the water ; 
put the softened glue into a double boiler 
and melt it, but do not bring it to a boil. 
Obtain six ounces of glycerin, warm it and 
add it to the melted glue. Add a few 
drops of carbolic acid. Mix thoroly and 
pour into your pan. A caramel pan is best. 

Receipt No. 2. — Add 3 ounces of water 
to l 1 ^ ounces of white glue. Heat in a 
double boiler until glue is melted. Then 
add six ounces glycerin and pour into pan. 
If too hard, add glycerin. If too soft, 
add glue. 

Receipt No. 3. — Dissolve 4 ounces of 
gelatin in one pint of cold water; then add 
one pint of glycerin. Pour into a double 
boiler, and when it comes to a boil pour 
into your pan. 

If bubbles appear on the surface, gently 
draw an edge of a sheet of writing paper 
over the surface before it cools. This will 
remove them. 

General directions for use. — Use noth- 
ing but unglazed paper, which can be pur- 
chased at any store where typewriter paper 
is sold. In ordering, be sure to state that 
you wish to use it for hektography. 

Use hektograph ink and a coarse stub 
pen. See that every stroke of the pen 
leaves a metallic luster when dry, else the 
work will not take. 

When the ink is dry, lay the face of the 
sheet which you have written or drawn, 
down on the hektograph ; press gently over 
the whole surface with the hand or soft 
cloth. After from two to five minutes (ac- 
cording to how many copies are desired) 
gently peel the paper off. 

From the impression thus made, repro- 
duce all the copies desired, laying one sheet 
on the hektograph at a time. 

Hektograph ink all prepared may be 
bought, or your druggist will put it up 
for you. The following is the receipt: 

Ink — Dissolve one dram of purple aniline 
in one ounce of water. 

The hektograph solves the supplemen- 
tary reading question. Each teacher, or any 
one who desires a number of copies of any 
text or drawing, can thus prepare as many 
as needed, at a very small cost. 

Contributed by F. H. SWEET. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



125 



iUPAMGfFJtf 



Our Amateur Laboratory Contest is open to all readers, whether subscribers or not. The photos are judged for best arrangement and efficiency 
of the apparatus. To increase the interest of this department we make it a rule not to publish photos of apparatus unaccompanied by that of the owner. Dark 
photos preferred to light toned ones. We pay each month $3.00 prize for the best photo. Make your description brief and use only one side of the sheet. 
Address the Editor, "With the Amateurs" Dept. 



AMATEUR RADIO STATION 
CONTEST 
Monthly Prize, $3.00. 
This month's prize-winner. 

CEDRIC E. HART'S EXCELLENT 
RADIO OUTFIT. 

The switch panel and cabinet, etc., shown 
in the accompanying photo have all been 




Cedric E. Hart's Radio Station at Salt Lake 
City, Utah, with Which He Obtained Highly 
Efficient Results. 

designed and built by myself, and with this 
cabinet I have no difficulty in receiving ail 
of the coast stations and the 
amateurs within a fair distance 
of here. I also hear Guam, 
Honolulu, Alaska, Panama, etc., 
quite regularly. I have a license 
and my call is 6SL. My receiv- 
ing set comprises the following: 
Navy 'phones, Blitzen tuner, 
Blitzen variable, Clapp-Eastbam 
tubular fixt condenser, Turney 
variable condenser, and an 
Audion cabinet. 

My transmitting outfit com- 
prises a 1K.W. Thordarson 
transformer, K.B. preventer, 
commercial key, home-made con- 
denser, Halcun rotary spark gap, 
home-made Telefunken type os- 
cillation transformer and a 
Blitzen hot-wire meter. The 
switches on the panel control the 
transformer, power, meter, condenser and 
inductance. 

This set, so far, has proven very efficient 
and, being as the panel has not been com- 
pleted two weeks yet, I think that Evans- 
ton, Wyo., is a pretty good distance to 
transmit for the short time I bave had it. 
Here's wishing the Experimenter prosperi- 
ty in its chosen path. 

CEDRIC E. HART. 

Salt Lake City, Utah. 



H. L. SCOTT TO RENEW HIS 
RADIO ACTIVITIES. 

Just recently 1 bought a copy of The 
Electrical Experimenter, the January 
number, and on reading it thru it has 
brought back pleasant memories of the 

THE MONTANA WIRELESS 
STATION OF HOWARD PASCOE. 

1 offer herewith a photograph of "The 
Montana Wireless Station" which consists 
of 1 K.W. Packard transformer, run on 
(110 volts A.C.) and a stationary spark 
gap. 

The receiving set consists of a loose 
coupler designed to receive up to 2(),U00 
meters and a loading coil for 4,000 meters. 

One (type D) receiving set of Marconi 
Wireless Telegraph Co. make which has 
a range of 2,000 to 4,000 meters or more. 
One pair of E. I. Co. Republic receivers, 
Standard wave meter, silicon and Audion 
detectors (Type R J 9). 

With this receiving set I am able to hear 
all the coast stations such as NPE, XPC, 
and the amateurs 7ZC, 7JN and many 
others. 

I have a little sub-station up in the moun- 
tains, 6,355 feet above sea-level. All my 
wiring is run in conduit. On account of 
the small space, the station had to be pho- 
tographed twice. 

I read The Electrical Experimenter. 
It is a fine magazine for the "Wireless 
Bugs." I will be glad to correspond or 
exchange photos of my station with other 
amateurs. 

HOWARD PASCOE. 
Butte, Montana (1129 East Galena) 



days when I operated my station. In fact 
it has thrilled me so much that I am go- 
ing to renew my operations with the old 
vigor. (Not until after the War — Ed.) 

It was when I lived at 158 Hamilton 
Street, East Providence, R.I., in 1909 and 
1910, that I had my best outfit. About that 





Uncle Sam May Find the Amateur Radio Station of Howard Pascoe, 
at Butte, Montana, of Valuable Assistance. 



Herbert L. Scott and His Radio Outfit, Which 
Has Done Good Work. 

time I believe I bought a detector from the 
Electro Importing Co. 

I am sending you a photo of my appa- 
ratus I used in 1910, which I still "have in 
storage. I hope you will find space in the 
columns of your magazine to reproduce 
this photo. For sending I used a three 
inch spark coil, run by six V. 60 A.H. 
storage batteries. The coil may be seen be- 
hind the loose coupler on the table ; over 
the coil on the board is a plate glass con- 
denser; above that is the spark gap and 
then the helix ; to the right is an anchor gap. 

The sending key may be seen on 
the extreme right of the table; 
the contact points are two dimes. 

For receiving I had a loose 
coupler of my own make, a 
Murdock tuning coil and a de- 
tector stand in which I used sili- 
con, together with a pair of 3,000 
ohm receivers, potentiometer, 
fixt condenser and Massie sealed- 
point electrolytic detector with 
double pole switch to throw in 
either system. I have heard Key 
West with this station. 

HERBERT L. SCOTT. 
Blackstone, Mass. 
(All radio men should read 
the notice in "Radio Dept." and 
on opposite page — Ed.) 



ATTENTION!!! 
Has your station photo appeared in 
"The Electrical Experimenter"? 
Why not purchase the electrotype 
and have some "real" stationery 
printed with your station picture 
on it? All of the "regular radio- 
bugs" are doing it. 



"NO MORE 'E.E.' " 

savs the newsdealer. "All sold out !" Did 
he tell YOU so last time? MORAL: 
Ask him to order a copy for you every 
month. Costs yon nothing to do so. The 
tremendous cost of paper does not allow 
excess printing, so we furnish dealers only 
with a sufficient amount of copies to supply 
their regular customers. If you are one, 
be sure to tell your newsdealer so, and give 
him your name and address, so he'll notify 
you by postal if you forget to call. 



126 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



A PROGRESSIVE CHICAGO RADIO 
EXPERIMENTER. 

My sending set included a ]/^ K.W. Blit- 
zen transmitter with rotary spark gap, op- 




One of the Honor Sets Among Chicago Radio 
Amateurs Was that of Mr. A. R. Gates. Mr. 
Gates Is One of the "Old Guard Boys," Hav- 
ing Been a Reader of "Modern Electrics." 



erated on 110 volts A.C. with a lamp bank 
in series with gap motor. Receiving set is 
result of reading Modern Electrics and 
The Electrical Experimenter for over 
2 l /2 years and is home-made 

The receiving transformer is designed 
for 3,000 meters with two variable con- 
densers : one across secondary and one 
shunted across 'phones. I have two crys- 
tal detectors, Ferron and galena, operated 
with a three point switch. Also a three 
element vacuum detector for long range 
work. The two D.P.D.T. switches on each 



side of Audion make a complete switch- 
over from crystal to Audion apparatus. 
Also to amplify weak signals there is a 
Muhi- Audi-Fone and 2,000 'phones. Sta- 
tion call 9NV. 
Chicago, 111. ARTHUR R. GATES. 

AMATEUR HEARS SPY RADIO 
CODE. 

Federal authorities hope to locate the 
sender of ■ aerial instructions to German 
spies thru the disobedience recently of 
Malcolm Ronberg, who has (or had) an 
amateur radio plant at his home, 6220 Uni- 
versity Avenue, Chicago, 111. 

Ronberg failed to obey the government 
mandate to dismantle radio stations. He 
decided to. "listen in" before complying. 

There was no sound for several minutes, 
then a peculiar unfamiliar call, repeated 
over and over again. Then there followed 
an even stranger grouping of letters, a code 
message. 

Ronberg hurried to the federal building, 
con f est he had been listening and turned 
over the message. It was sent to federal 
operators at Great Lakes station. They, 
too, failed to decipher it. But the fact that 
Ronberg received it in his small amateur 
station has helped the searchers to trace it. 

Ronberg was thanked, instructed to dis- 
mantle his plant by midnight or go to jail, 
and a squad of detectives was hurried out 
under orders of John C. Dillon, chief radio 
inspector of Chicago. 



Young chickens treated with electricity 
by a London experimenter grow more rap- 
idly than those raised without treatment. 



DE FOREST GIVES $5,000 TO AMER- 
ICAN DEFENSE SOCIETY. 

Dr. Lee de Forest, the wireless inventor, 
has offered the American Defense Society 
$5,000 as the nucleus of a preparedness 
fund. 



A RADIO ECHO FROM 
LARCHMONT MANOR, N.Y. 

Herewith is a photo of my radio station. 
The sending set is composed of a 1 inch 
Bull-Dog spark coil, a sending condenser, 
spark gap, key and transformer. In my 
receiving set there are three loading coils, 
two fixt condensers, a double slide loose- 




Clarence de Witt Rogers, Jr., a Rising Radio 
Student, of Larchmont Manor, N. Y. 



coupler, a silicon detector and a de Forest 
Audion. I have two 1,500 ohm 'phones 
and one 500 ohm 'phone. 

CLARENCE de WITT ROGERS, JR. 
Larchmont Manor, N.Y. 



Fort Wayne Radio Association of 
Indiana. 

The Fort Wayne Radio Association of Indiana 
began the New Year with the installation of the 
following new officers: G. Carter, President; R. 
Parvin. Vice-president ; D. W. May, Secretary and 
F. Hall, Treasurer. 

We have had some very successful meetings 
during the winter months. Our best and most- 
lookt for speeches are given by Mr. Carter, who, 
besides giving good talks, has formulas worked 
out, which enables us to see if we are getting 
the most out of our transmitters. 

In an effort to lessen interference, we have a 
"QRM Committee" to report at our meetings every 
two weeks. 

Several of our members have some fine long- 
distance work to their credit. They are 9 P C, 
9 W F, 9 V Y, 9 T A, 9 K G and 9 U H. 

We will be glad to correspond with other clubs 
so as to exchange ideas. Address communica- 
tions to n. W. May (9 TJ H), 3021 Hoagland 
Avenue, Fort Wayne, Ind. 



Alpena, Mich., Has a Radio Club. 

The Alpena Radio Club of Alpena, Mich., has 
been formed for the advancement of wireless 
telegraphy. Meetings are held every Thursday 
evening at the home of the President, 516 .State 
Street. The officers are: President, W. A. Pot- 
ter; Vice-president, Hugo Sorenson; Secretary and 
Treasurer. P. B. Alger; and Consulting Engineer, 
Mr. J. Mulavey. All communications should be 
addrest to the Secretary, P. B. Alger, 119 State 
Street, Alpena, Michigan. 



Allentown, Pa., Radio Men Reorganize. 

The Inter-City Radio Association of Allentown. 
Pa., organized October 2S. 1915, recently re- 
organized under a new name to be known hence- 
forth as The Y. M. C. A. Radio Association of 
Allentown. 

The art of field signaling and code receiving 
are now being taught to the members by the Chief 
I )perator, Harvey Zinger. The following are the 
new officers of the Association: D. H. Goodling, 
President; Stanton Nadig, Vice-president; Blair 
Cunningham, Secretary; Arthur Breisch, Treas- 
urer; Harvey Zinzer, Chief Operator. Correspond- 
ence with similar organizations will be appreciated. 
Address all communications to D. H. Goodling, 
330 N. Madison Street. Allentown, Pa. 



Radio Activities in Kansas City, Kansas. 

The Kaw Valley Radio Association has been 
formed by the amateurs of this city. The club to 
date has seventeen members with officers as fol- 
lows: Ralph Rehm, President; Parker Wiggin, 
Vice-president; Harlow Eppert, Secretary; Joe 
Harlan, Treasurer. 



Amateur News 

The club is progressing rapidly and is certain 
to obtain more members in the near future. As 
yet we have no set but expect to obtain one 
soon. Regtdar meetings are held every Thursday 
night at 7:30. All communications should be 
sent to Harlow Eppert, 841 State Avenue, Kansas 
City, Kansas. 

Y. M. C. A. Wirtless of Salesburg, HI., 
Sends Basketball Scores. 

The wireless club of the Y. M. C. A. recently 
sent out the scores of the basketball tournament. 
These scores were sent out three times a day, at 
the close of each session, 12:00 o'clock noon, 6:00 
o'clock after the afternoon session and at 10:00 
o'clock after the night session. The towns which 



ALL RADIO AMATEURS 

ATTENTION! f 

As all of you know the United I 

f States is now in a state of war with 1 

| Germany, and as true-blood Amer- [ 

1 ican citizens, we are, each and | 

1 every one of us, duty bound to obey 1 

1 the mandates of the U. S. Govern- 1 

1 ment officials. The Navy Depart- 1 

1 ment has been delegated by our 1 

I President to close all amateur or | 

1 experimental radio stations, no 1 

| matter whether equipt for transmit- j 

1 ting or receiving, licensed or un- | 

1 licensed, and therefore we shall all 1 

| have to abide by this decree, ] 

I whether we like it or not. \ 

Therefore, beginning with the 1 

I next issue of "THE ELECTRI- I 

j CAL EXPERIMENTER," we will 1 

1 endeavor to feature the Electrical 1 

| Laboratories in preference to any | 

1 radio stations in the awarding of § 

1 the monthly prize of $3.00 in this | 

1 department. Now is the time to f 

1 get busy and freshen up your elec- | 

1 trical apparatus, and incidentally 1 

| improve your understanding of f 

1 electrical matters, which perhaps | 

1 you have unwittingly slighted to a f 

| large degree in your pursuit of 1 

radio-telegraphy. Let her go, boys! | 



were connected with Thursday night were Rock 
Island. Peoria, Springfield, Cambridge, Genesee 
and Monmouth. 

Roy S. Landon had charge of this work, and 
under his supervision the boys are showing an 
unusual amount of interest. Recently the boys 
received and sent messages to the University of 
Iowa station. 



Worcester Tech. Wireless Club is Busy. 

The Wireless Club of Worcester Tech., elected 
Warren B. Burgess, '16, of Hyde Park, chief 
operator in charge of the maintenance of the 
Tech. station. Twelve new members were voted 
in and plans were discust for a series of talks 
to be given by Instructor Carleton D. Haigis of 
the physics department on the theory of electric 
waves and other subjects interesting to wireless 
students. The president was empowered to ap- 
point a committee to draw up plans of a new an- 
tenna to be erected this year. 

Hoboken, N. J., Wireless Amateurs 
Secure Clubrooms. 

The Hudson City Radio Association has secured 
rooms, at 541 Central Avenue, Jersey City, where 
they have erected a large aerial and a sensitive 
receiving outfit. Code practise is given every 
night to those who desire it. 

Election of permanent officers was held with 
the following results: President, Joseph F. Grece; 
Vice-president, William Biedenkapp: Financial Sec- 
retary. Frank V. Bremer; Recording Secretary, 
Clarence Maves; treasurer, William S. Davidson. 

All amateurs in Hudson County are invited to 
join the association. Address Clarence Maves, 
Secretary, 90 Ferry Street, Jersey City, N.J., for 
an application blank. 

Waterbury Radio Club of 
Waterbury, Conn. 

The Waterbury Radio Club was formally organ- 
ized recently by 15 local young men who are in- 
terested in wireless telegraphy. King Sam, the 
Chinese young man who is probably the only Chi- 
nese wireless operator in New England, took the 
initiative in banding the local operators together 
and the meeting was held in the wireless room 
at the Boys' Club. E. C. Glavin, an inventor and 
a pioneer in wireless telegraphy study, attended 
the meeting and was named as honorary chair- 
man. The other officers are Robert W. Culbert, 
Jr., Chairman; Clinton A. Fitch (operator of the 
Boys' Club wireless set), Secretary and Treasurer. 
The membership of the club is 15 just now and 
it is planned to increase it to 25 later. 

The publicity secretary for the club is King 
Sam. He stated that it is the purpose of the 
organization "to further advance and foster the art 
of wireless telegraphy in this city." 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



127 



EXPERIMENTAL CHEMISTRY. 

{Continued from page 123) 
chloric acid, and proceed to neutralize them 
in the same manner. After they are neu- 
tralized, and after applying the litmus tests, 
place in a clean evaporating dish and 
evaporate the solution to dryness. The 
equation for this reaction is practically the 
same except that Potassium is substituted 

TABLE OF VALENCE. 

TABLE NO. 1. 

Metals and Positives Non-Metal and Nega- 
Radicals. ' ti"- Radicals. 



c 
o 

% 


Dyad. 


Triad. 


Tetrad. 


Monad. 


Dyad. 


Triad. 


Tetrad. 


H 


Mg 


As 


Pt 


F 


( ) 


N 


c 


Na 


Ca 


Sb 


Sn 


CI 


S 


P 


Si 


K 


Sr 


Bi 




Br 


so 3 


B 


SiO« 


Ag 


Ba 


An 




I 


so 4 


P0 3 




Hg 


Pb 


Fe 




NO. 


co 3 


P0 4 




NH, 


Cu 


Cr 




N0 3 


c 2 o 4 


AsOs 




CH :! 


Cd 


Al 




CIO 


CaHiOa 


As0 4 




C2H5 


Zn 






C103 








Co 






C10s 










Ni 






CIO, 










Hg 






Br0 3 










Sr 






10, 










Fe 






C 8 H 3 2 









As we have been constantly referring to metals, 
non-metals, positive radicals and negative radicals, 
the above table is given now, before the study of 
valence is taken up, so that readers may refer 
to it when metallic and non-metallic elements are 
mentioned. 

for the Sodium, as : — 

KOH + HC1 = KC1 + H,0 
Potassium Hydrochloric Potassium Water 
Hydroxid Acid Chlorid 

EXPERIMENT NO. 56— 

Dilute 1 part of Sulfuric acid with three 
or four parts of water, and place in a 
small-lipt beaker or test tube as in the 
preceding experiments, and neutralize. 
When neutral, filter, and place in an evap- 
orating dish and evaporate to dryness. 
Either one of the following equations will 
take place : — 

KOH 4- H,S0 4 = KHSO4 + H 3 
Potassium Sulfuric Potassium Water 

Hydroxid Acid [Acid] Sulfate 

or 



II 

Aluminum Jl - 
Ammonium M f ' 
Antimony Sb » 
Barium Be • 
Bismuth Bi ' 
Cadmium 
Calcium 
Chromium 
Coba/f 



Hydrogen 
Iron 
Iron 
Lead 



Cd- 
Ca - 
Cr""' 
Co ' 
Cu ■ 
H • 
re ' 
fe - 



Jo 

I «X • BXBBXXXX • • XB 
IBBBBBBBBBBBBBBB 

XBXX^»XXXBX^X 

• i*ii»rrr*ni 
ra*BB* • *xr«BB 

•B*BBrBBB*rBB 

•BXBB* *XXr*BB 

•□□r «bb 
BBr*nnr*^B 



vum Mg • 
Mongonese Mn 



Mercury 
Mercury 
Hic/iel 
Potassium 
Silver 
Sodium 
Strontium 
Tin 
Tin 
Zinc 



\*v 

I»X 
l»X 

l» • 

j.X 

l« • , 

IBXI 

I* • •B*BBX«COr«__. 
)• • • BXBBFXBDr • BBT 
l» • •WWW • »VV *B 
I* •rfl«BBBBBB**BB 
I* • •■•BBr»D» 
••v *BX*B 
!• •Xr«BBrBXXBX»^ 
I* • *B*BB* •□□r*Bfl 



r • • •□□bx»i 



■•r •■•■■raxB* •■■ 
■ • • •■ ^» • 

B»XXBXXBXXX»B«T1B 

B»x * *r*mm* 



X- Blank 
H ■ Soluble in wafer 
□ - Insoluble in irofSr and acids 
• • Insoluble in iroler bat soluble i 
W m Slightly soluble in water 
^'Jolublein /voter irtfh very /idle acid. 



Table of Solubilities. 



H 2 
Water 



2K0H 4- H 2 SOi = K 2 S0 4 + 
Potassium Sulfuric Potassium 

Hydroxid Acid Sulfate 

The reasons that two equations of re- 
action which may take place is more fully 



explained in the opening of this article. 

If desired Sodium Sulfate [Na 2 SOi] can 
be prepared in the same manner as above. 

EXPERIMENT NO. 57— 

Neutralize Ammonium Hydroxid 
|NHiOH] by the preceding methods, and 
Nitric Acid [HNO*]. Make the tests with 
the red and blue litmus papers. Evaporate 
as before. The product of tin's neutraliza- 
tion cannot be evaporated to complete dry- 
ness, owing to the fact that the nitrat 
breaks up. 

NHjOH 4- HNO., = NHjNO.i 4- H 2 
Ammonium Nitric acid Ammonium Water 
Hydroxid Nitrat 

The above salts which were prepared by 
the neutralization of acids and bases, are 
soluble salts. 

Salts can also be produced by the action 
of acids on metals ; below are given methods 
of preparing chlorids, sulfats and nitrats. 

EXPERIMENT NO. 58— 

Put into a clean test tube about 5 grams 
of zinc and pour over it about 10 cc. of 
dilute hydrochloric acid. It will be re- 
membered that this experiment was per- 
formed in a previous installment, [Hydro- 
gen, Experimental; January, 1917, issue 
Electrical Experimenter]. Apply a lighted 
splint to the mouth of the tube and notice 
any familiar action. After the action stops 
pour the liquid upon a filter ; then evap- 
orate the Filtrat [the solution obtained 
after filtering] in an evaporating dish, and 
note what is left. 

The reaction for this experiment is : 

Zn 4- 2HC1 = ZnCl 2 4- H 2 

Zinc Hydrochloric Zinc Hydrogen 

Acid Chlorid 

The gas which escapes from the tube is 
hydrogen, and by applying a lighted splint 
to the mouth a slight explosion should be 
caused to occur. The product obtained in 
this experiment is Zinc Chlorid [ZnCl 2 ]. 

EXPERIMENT NO. 59— 

Pour about 10 cc. of dilute Sulfuric acid 
[H2SO4] made by pouring 3 or 4 cc. of 
strong Sulfuric acid to the 
water, about 10 cc, stirring the 
liquid constantly, and adding 
the acid in small quantities. 
[Never add the water to the 
acid], on about 5 grams of 
scrap iron. It may be neces- 
sary to heat the mixture over 
the Bunsen burner in order to 
produce better action. After 
the action has proceeded for 
some time remove from the 
flame, and add about 5 or 10 cc, 
[after the liquid has been fil- 
tered]. After the water has 
been added to the solution, 
place in an evaporating dish 
and proceed to evaporate. The 
reaction for this experiment is : 

Fe + H 2 SOi = FeS0 4 + H 2 
Iron Sulfuric Ferrous Hvdrogen 
Acid Sulfate 

EXPERIMENT NO. 60— 

Mix 5 cc of water with 
about 5 cc. of Nitric acid 
[HNOs]. Place about 5 grams 
of copper scraps in a test tube 
and add the 10 cc. of Nitric 
acid, prepared as above. If ac- 
tion does not take place, heat 
gently over a Bunsen burner. 
A deep green solution will 
form, and after the action has 
stopt, add about 5 or 10 cc. of 
water and slowly evaporate, as 
before. If the evaporation is 
carried to dryness the nitrat 
will break up into the insoluble 
oxid, which will manifest a black color. 
To avoid this action the liquid need not 
be completely evaporated, but it may 
(Continued on page 154) 



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"MAN-HUNTING" WITH THE 
ELECTRIC CALLING 
SYSTEM. 

One, two. three — pause — one, two = 32 
on the electric calling system here illus- 




Keyboard of Electric "Man-Hunting" 
Machine. It Instantly Summons the 
Desired Party to the Nearest Tele- 
phone. 



trated. It is the prince of man-hunters, 
serving as it does to quickly summon any 
particular individual to the nearest tele- 
phone, no matter in what part of the plant 
or shop he may be at the moment. 

The Electric Calling System is primarily 
the operating instrument, which is con- 
nected by wiring to a line of signals con- 
sisting of either bells, horns, buzzers, lights 
or whatever other electrical devices it is 
desired to use. These signals are dis- 
tributed thruout the establishment in such 
a manner that every foot of floor-space is 
within the sound radius of at least one 
signal. 

The Calling System has no direct con- 
nection with the telephone, but is usually 
located, for convenience, near the tele- 
phone central station, within easy reach 
of the operator's hand. The operating in- 
strument may, however, be placed any- 
where on the circuit. 

This System operates on a voltage of 
either 110 or 220, A. C. or D. C. It is 
always in service and there are no bat- 
teries to cause 
trouble or to 
be recharged. 
The consump- 
tion of cur- 
rent is most 
economical. 

The instru- 
ment is made 
in one univer- 
s a 1 model, 
which has a 
calling capac- 
ity of 45 dif- 
ferent code 
numbers. 
There is no 
limit to the 
number of 

signaling devices which the instrument will 
control, provided sufficient current is let 
into the line to operate them. 

The signals are controlled by eight small 
levers which form the number combinations. 




THE ELECTRICAL EXPERIMENTER 




June, 1917 



PATENTS 



An Electric Photometer 

(No. 1,218,946; issued to Clayton 
Laing.) 

This device embodies a clever 
electrically operated photometer for 
use by photographers in accurately 
calculating the proper exposure for 




any strength of light and any size 
lens opening. The instrument com- 
prises a suitable light filter and co- 
operating shutters, so that ordinary 
daylight may be properly compared 
with a standard of light incorporated 
in the photometer. The light stand- 
ard is composed of a small electric 
bulb, and a dry battery with suitable 
switch. When equal amounts of 
light penetrate two special trans- 
lucent blocks, they appear as one 
block; the two halves of the block 
perfectly balancing, so that natural 
and artificial rays are of equal in- 
tensity. 



Antenna for Aeroplanes 
(No. 1,219,550; issued to Walter 
Hahnemann. ) 
An improvement in design of 
wireless antennae for aeroplanes 
comprising a bamboo or other mast 




supporting one or more insulated 
flat-top_ aerials. The "ground" ele- 
ment is compensated for by utiliz- 
ing the metallic aeroplane structure; 
the "aerial" element being cared 
for by the special antenna here 
shown. The inventor has paid par- 
ticular attention to the correct de- 
sign of aeroplane antennae, with 
respect to the proper maintenance 
of the stability and operating char- 
acteristics of the aeroplane itself 
and claims that the addition of his 
antenna to an aeroplane will not 
cause it to be unbalanced in flight 
or in maneuvering. 



Pool Table Register 

(No. 1,220,420; issued to William 
H. Heffley.) 
An interesting and practical elec- 




tro-mechanical device for register- 
ing the results of a game of pool, 
etc., whereby the pool ball as it 
falls into a pocket, closes an elec- 
trical contact. This causes a set of 



magnets to operate a pawl and 
ratchet connecting with the indi- 
cating needle in the manner shown, 
and the dial may be marked off in 
any suitable style and colors. The 
device can be attached to any pool 
table without altering or damaging 
it, and each table pocket is con- 
nected up to the electrical score- 
board. 



Electrolytic Gas-Generator 

(No. 1,219,966; issued to Isaac H. 
Levin. ) 

Electrolytic apparatus designed to 
produce hydrogen and oxygen gases 
by subjecting water containing a 
small quantity of a suitable electro- 
lyte, such, for example, as potassium 
hydroxid, sulfuric acid, etc., to the 
action of an electric current, which 




is caused to flow there-thru from 
one electrode to another, both elec- 
trodes being submerged in water. 
The solution is decomposed in the 
well-known electrolytic manner, oxy- 
gen being liberated at the positive 
electrode and hydrogen at the nega- 
tive electrode. This invention re- 
lates particularly to an electrolytic 
gas generator in which the liquid 
acted upon is contained in a suitable 
receptacle, having two sets of in- 
sulated electrodes entirely indepen- 
dent of the receptacle proper. 



Radio Arc Transmitter 

(No. 1,220,072; issued to Louis 
Cohen.) 

Hill 




loop circuit will have less resistance 
than the antenna circuit, as it is 
closed and practically all of the 
high frequency oscillations produced 
will flow in this circuit. When the 
key is opened, the arc oscillations 
will charge the aerial instead. 



Oscillating-Current Generator 

(No. 1,221,034; issued to Lee de 
Forest.) 




An improved method of develop- 
ing powerful high frequency oscilla- 
tions with a vacuum tube generator 
suitably associated with one or more 
oscillatory circuits. The inventor 
provides an evacuated bulb contain- 
ing mercury electrodes, which pro- 
duce a mercury vapor arc within 
the bulb. Two cold electrodes 9, 
and 10, are utilized, 9 being water 
cooled, and 10 being a bent hollow 
grid. An oscillating circuit is as- 
sociated with the two cold electrodes 
9 and 10. A second oscillatory 
circuit is provided thru inductance 
20, and capacity 21. With this ar- 
rangement, the oscillations produced 
in the first oscillatory circuit are 
increased in intensity when the 
period of the second oscillatory cir- 
cuit is made equal to that of the 
first. The output or ''load" circuit 
comprises ground 24, inductance 22 
and aerial 23. 



Combination Radio Receiver and 
Detector 

(No. 1,219,888; issued to Frank 
Wallberg.) 




An extremely compact "pocket" 
wireless set, comprising a tuning 
inductance, crystal detector and tele- 
phone receiver, all in the space re- 
quired for an ordinary watchcase 
telephone receiver. The telephone 
receiver and detector are connected 
in parallel, and this unit in series 
with the aerial, ground and tuning 
coil. The latter is adjustable by 
means of a switch; the tuning coil 
is wound about the shell of the 
receiver, and the detector is ex- 
tremely small, being placed within 
the receiver-magnet chamber as 
shown. The device is held to the 
ear when in use, and the switch 
turned until the signals come in the 
loudest. . 



Electric Land-Torpedo 

(No. 1,219,028; issued to Abraham 
Must.) 



Instead of utilizing the "com- 
pensation wave" method of radiating 
telegraphic signals by means of a 
radio arc type transmitter, the in- 
ventor has developed a novel scheme 
which operates as follows: With 
the Poulsen system, energy is con- 
tinuously transmitted, but with this 
arrangement energy is radiated only 
as the dots and dashes are sent out. 
During the "space" periods no cur- 
rent is radiated from the aerial, the 
high frequency oscillations being 
shunted thru a variable resistance 
key 8, condenser 5-a and inductance 
2-a. This does not affect the opera- 
tion of the arc and no appreciable 
sparking occurs. When the vari- 
able resistance key 8, is closed, the 

COPIES OF ANY OF THE ABOVE PATENTS SUPPLIED AT 10c. EACH 




A novel invention comprising an 
electrically driven or propelled land- 
torpedo possessing several unique 
features. As shown in the illustra- 
tion, the design comprises two sec- 
tions; the forward compartment con- 
taining the charge of explosives and 
detonating means, while the pivoted 
rear unit contains the electric driv- 
ing motor and necessary gears. The 
land-torpedo is dispatched from a 
trench, and is under constant con- 
trol of a soldier in the trench. It 
should prove useful in destroying 
barbed wire, and other impediments, 
as when it has reached the desired 
spot, the operator simply pushes an 
electric button which detonates the 
explosive charge in the war-head of 
the torpedo, thus destroying the 
obstruction. The torpedo hauls its 
electric feed wires after it, as it 
ambles away from the trench. 



Electric Gas Buoys for Submarine 
Warfare 

(No. 1,222,498; issued to Joseph A. 
Steinmetz.) 




Something quite new in the realm 
of war machinery and comprising 
a series of highly charged poisonous 
"gas buoys," which may be attached 
to the exterior of the submarine, 
and which are held in clamps, elec- 
tro-magnetically controlled from the 
interior of the submarine. The lat- 
ter may submerge in proximity to a 
hostile war-ship and release one or 
more of the gas buoys. These float 
to the surface and even tho struck 
by shell-fire, they will proceed to 
liberate a cloud of deadly gas fumes, 
which are supposed to eventually 
overcome the crew of the war-ship. 
The gas buoys may be released and 
immediately cut free, or they may 
be maintained in position by a cable 
as shown, so that they will not 
drift away before their task is fin- 
ished. 



Hood for Concealing Telephone 

(No. 1,221,919; issued to Lillian A. 
Strasburger.) 




This invention provides a specially 
devised concealing hood for cover- 
ing the telephone instruments in 
"My Lady's Boudoir," etc. As 
shown in the illustration, the device 
comprises a wire frame-work pro- 
vided with a spring clip and a doll's 
head. The attachment is suitably 
drapt and at the rear it is pro- 
vided with a sliding curtain. To 
use the telephone, it is but neces- 
sary to grasp the skirt of the figure 
and turn the whole outfit around 
180 degrees, when the rear curtain 
can be slid sideways and the re- 
ceiver moved from the hook. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



129 



Phoney Patents 



Under this heading are publisht electrical or mechanical ideas which 
our clever inventors, for reasons best known to themselves, have as yet 
not patented. We furthermore call attention to our celebrated Phoney 
Patent Offizz for the relief of all suffering daffy inventors in this country 
as well as for the entire universe. 

We are revolutionizing the Patent business and OFFER YOU THREE 
DOLLARS! $3.00 FOR THE BEST PATENT. If you take your Phoney 
Patent to Washington, they charge you $20.00 for the initial fee and then 



you haven*t a smell of the Patent yet. After they have allowed the Pat- 
ent, you must pay another $20.00 as a final fee. That's $40.00 ! ! WE 
PAY YOU $3.00 and grant you a Phoney Patent in the bargain, so you 
save $43.00 ! ! When sending in your Phoney Patent application, 
be sure that it is as daffy as a lovesick bat. The daffier, the better. 
Simple sketches and a short description will help our staff of Phoney 
Patent examiners to issue a Phoney Patent on your invention in a 

jiffy. 



No. (I 



Phoney Patent Offizz 

S. T. Raphangr of Rushour, D. T. 

SELF PROPELLED TROLLEY 



Patent Rattled 



To Whomsever II Might Concert: 

Be it knowed to all unknown and all 
other straphangers at large, as well as all 
those confined in solitary confinement 
thruout the world, that I Salomon Tad- 
dens Raphangr of the City of Rushour 
in the State of Deliriumtrcmens, have de- 
vised, designed, designated and developed 
an invention of the most far reaching con- 



all the power and lots to spare besides, 
being furnished by the swaying straphang- 
ers themselves. The excess power can be 
used to light the car and charge a stor- 
age battery, which in turn may drive the 
car when traffic is light. But this is by 
no means all. By providing all seats with 
a spring attachment, the seated passengers 
will bump up and down nicely, and I found 



turn drives the motors 5 under the car. 
The motors being geared to the axles drive 
the wheels of the car. The car wheels 
being off center, as observed, will give the 
trolley car a pitching motion like a ship 
in a swell. This greatly aids in more effec- 
tively swaying and bumping the passengers. 

The seated passengers when rising up 
and down on their spring seats operate 




Straphangers All Over the Universe As Well As Trolley Car Magnates Will Rejoice At This New Invention. Not Only Do the Sway- 
ing Passengers Now Propel the Car, But They Experience All the Variegated Experiences of a Sea Trip and All for a Nickel. 



sequences to a long suffering traveling pub- 
lic. 

It is a well known, altho deplorable fact, 
that the modern trolley car for economic 
reasons of all traction companies are equipt 
with rather oval as well as "flat" wheels. 
The tracks too, are of the scenic railway 
type, fashioned after the camel's back, i. e., 
hill and valley with 15 hills and 29 val- 
leys to the running yard. These modern 
refinements are necessary to shake up and 
bump the cars vigorously, this action be- 
ing required to pack the passengers tightly 
into the car and to jingle the passengers' 
nickles, so the latter can be extracted easier 
for the conductor's rake-off. 

Having in mind these points and know- 
ing that passengers always sway to and 
fro in all our trolleys in a truly alarming 
manner, I conceived the brilliant idea of 
utilizing this prodigious energy, now going 
to waste. In my researches I quickly found, 
that if you start the car on an incline, 
no further power is required to propel it, 



this to be far more pleasing than being 
bumped up and down on hard seats. It 
is also very healthy, for the digestion is 
greatly improved, especially after heavy 
meals. It will ''settle" the heartiest meal 
wonderfully. If the public comes to rea- 
lize this it will patronize my new self- 
propelling trolley in a manner undreamt 
of by the most voracious traction com- 
pany shareholder. No power house nor 
trolley wires being required, the company 
will make enormous profits, and it will 
be able to issue a package of chewing gum 
and 10 'trading stamps free with every 
nickel ride. 

Referring to the patent drawing we find 
that 1 is the strap on which the strap- 
hanger navigates. Every time he sways he 
exerts a pull of about ISO lbs. on the strap, 
and by means of a pawl and ratchet ar- 
rangement mounted on a common shaft 
passing thru the length of the trolley, the 
shaft begins to rotate. The power is then 
conducted by belts 3 to dynamo which in 



gears 4 and the resulting power is also 
conveyed to the belts 3, this furnishing 
additional power. 
What I claim is: 

1° A wireless trolley, operated solely by 
Straphangers. 

2° A self propelled fat reducing trolley 
stimulating digestion and preventing in- 
digestion. 

3° A trolley car giving passengers all 
the experiences of a sea trip for a nickel. 

In consternation whereof, I have there- 
fore resolved and caused to he appended 
and imprest hereunto and hereunder the 
crest of my family shoe tree with my left 
uppermost hind foot this 16th day after 
the "ad'Vent of any deceased maiden aunt's 
German measles, in the presence of three 
witnesses. 

S. T. RAPHANGR. 
Wittynesses: By his Attorney, 

A. W. Gowan, Thomas W. Benson, 
I. M. Indutch. Phila., Pa. 
C. U. Titout 



130 



THE ELECTRICAL EXPERIMENTER 



June, 1917 




Lg3 




QUESTION BO 



This department is for the sole benefit of all electrical experimenters. Questions will be answered here for the benefit of all, but only 
matter of sufficient interest will be publisht. Rules under which questions will be answered: 

1. Only three questions can be submitted to be answered. 

2. Only one side of sheet to be written on; matter must be typewritten or else written in ink; no penciled matter considered. 

3. Sketches, diagrams, etc., must be on separate sheets. Questions addrest to this department cannot be answered by mail free of charge. 

4. If a quick answer is desired by mail, a nominal charge of 25 cents is made for each question. If the question entail considerable re- 
search work or intricate calculations a special rate will be charged. Correspondents will be informed as to the fee before such questions are 
answered. 



RECORDING VOLTMETER. 

(785.) J. Hassel, Baltimore, Aid., asks: 
Q. 1. What is a recording voltmeter? 
A. 1. A recording voltmeter is an in- 
strument which permanently records the 
potential that exists between points in an 
electric circuit during any definite period. 
It consists of nothing more than an ordi- 



Standard Vo/tmeter\ 




Connections for Calibrating a Recording 
Voltmeter With the Aid of a Standard Volt- 
meter and Two Rheostats. 



nary voltmeter, the armature or moving 
element of which carries a small writing 
pen, that traces a curve on a moving strip 
of paper. The variation of the e.m.f. in 
the circuit is indicated by the variation of 
the traced curve. The strip of paper which 
receives the record is moved by a special 
clock mechanism. 

Q. 2. For what purpose are these in- 
struments most adapted? 

A. 2. They are generally employed in 
power-houses, where it is required to know 
the exact voltage conditions of the line 
during certain periods of the day. 

Q. 3. Are these instruments sufficiently 
accurate to warrant their use in laboratory 
work? How are they calibrated? 

A. 3. No. Most of them require a large 
correction factor. Their accuracy depends 
upon the degree of voltage variations, as 
the friction between the pen and paper is 
somewhat great when the moving element 
is caused to move frequently. 

The waring diagram herewith gives con- 
nections of a recording voltmeter for cal- 
ibrating the same with a standard volt- 
meter. 

IMPULSE EXCITATION. 

(786.) Paul Magdale, Hackensack, N. J., 
desires to know : 

Q. 1. What is meant by impulse excita- 
tion? 

A. 1. Impulse excitation is a method of 
exciting the antenna by means of an oscil- 
latory circuit which is highly damped and 
the coupled secondary or antenna circuit 
receiving an impact or shock from the pri- 
mary circuit, and permitting this secondary 
circuit to oscillate with as little damping 
as possible. The primary oscillatory cir- 
cuit is so adjusted or tuned that a single 
impulse is produced. 

Q. 2. Is the quenched spark gap system 
operated on the impulse excitation prin- 
ciple ? 

A. 2. Yes ; but it is not an ideal im- 
! pulse excitation, since the primary of the 
circuit is not permitted to be highly damped. 
Furthermore, the oscillations of the pri- 
mary are periodically cyclonic and not im- 
pulsive or semi-per.iod oscillations, as that 



obtained from an ideal impulsive excita- 
tion transmitter. 



RADIO BOOKS. 

(787.) Andrew Colly, Oyster Bay, L. I., 
asks : 

plllllllillllllllllll 

TO OUR FRIENDS. 

B Do you realize that not one day B 

jj passes when we do not receive from jj 
M 150 to 250 or more letters addrest to 

f the "Question Box''? If we were to ji 

g publish all the questions and answers B. 

B we would require a monthly magazine B 

8 five or six times the size of The B 

j§ Electrical Experimenter with no = 

B other matter but questions and an- B. 

B swers! Of late the influx of letters Bj 

M has become so heavy that several of g 

B our associates have been forced to B 

HI discontinue important editorial work, j§ 

B in order to answer the mail. This we §1 

g| are certain you do not wish. You do g 

B not want your magazine to lower its B 

g present high standard. You want the 8 

fjj best, the very best, and you know we B 
fg never' have failed you yet. 

g Moreover the multitude of letters B 
S arc wholly unnecessary. Most of the S 
W= questions zvc are asked every day B 
g have been answered before in the B 
B Question Box. Therefore ere you B 
g sit dozen to write to us, look over B 
B your back numbers and nine times jj 
B out of ten you will find the answer, B 

jjj We strive hard to publish only B 
g such matter as has not appeared be- m 
B fore in our columns, and for that B 
B reason only a small fraction of que- B 
jg ries of those received by us are ac- B 
B tually publisht. 

S Kindly note, therefore, that in the B 
jj future zve cannot, in your own in- B 
B_ tercst, answer questions by mail, free m 
B of charge. B 

jj For questions requiring immedi- B 
g ate answer our fee is 25c. for the =. 
B first ordinary question and 25c. for M 
H each additional question. We will j| 
Ij gladly advise fee for special ques- \ 
B tions entailing considerable calcu- B 
j§ lations or research. Stamped 1 * and B 
B addrest envelope should be enclosed B 
3 with the queries and, moreover, any B 
B sketches accompanying them should B 
jj be made on separate sheets. And B 
B please be brief. B 
THE EDITORS. 1 
= 1 ^ \ii : 1 ' 1 , I' -J'.' |i' 'Z^,,- 

Q. 1. Where can I buy wireless books 
describing in detail the complete theory of 
radio engineering, and also a text-book 
giving complete data as to the design and 
operation of radio apparatus? 

A. 1. We would recommend the follow- 
ing books, which we believe will give you 
all the desired information : By J. A. 



Fleming, "The Principles of Electric Wave 
Telegraphy," $10.00; by J. Zenneck, "Wire- 
less Telegraphy," $4.00; Eccles' "Wireless 
Telegraphy and Telephony," $3.50. We w.ill 
send any of these books on receipt of 
price. 

Q. 2. Are all the Radio Amateurs of 
this country to remove their aerials and 
apparatus in this present crisis? 

A. 2. Orders have already been given 
to instruct all Amateurs thruout the coun- 
try to remove their aerials. The instru- 
ments were not asked to be removed or 
confiscated by the authorities up to the 
present time. 

WIRING DIAGRAM. 

(789.) Peter Hancock, Toledo, O., 
wants : 

Q. 1. A wiring diagram of a short wave 
regenerative Audion receiving outfit. 

A. 1. The appended diagram gives the 
proper connections. 

Q. 2. How can I eliminate the noises 
produced in the receiver when the Audion 
is in operation? This effect is even ob- 
tained when the receiving instruments are 
disconnected from both the aerial and 
ground. 

A. 2. The noise which you are experi- 
encing is due to a constant electrical charge 
on the grid of the Audion, which causes 
the grid condenser to charge and discharge 
unperiodically ; consequently affecting the 
receivers. This trouble might be eliminated 
to a certain degree by shunting a high re- 
sistance "leak" path across the grid con- 
denser. It must be a non-inductive leak 
and can be made very readily by marking 
upon a sheet of paper a pencil mark and 
connecting the ends of this line across the 
condenser. A little patience in making the 
proper thickness of line will be required 
before proper results can be obtained. 




Hook-up for a Short Wave Regenerative 
Audion Radio Receiver. 



WAVE LENGTH OF ANTENNA. 

(790-A) Thomas Lowman, East Pitts- 
burgh, Pa., inquires : 

Q. 1. Can you give me the wave length 
of an antenna which consists of four wires 
60 feet high, 100 feet long, and the wires 
separated 2 feet? 

A. 1. The wave length of this antenna 
is 300 meters. 

Q. 2. Suppose I desire to use this an- 
tenna with a transmitting station, which 
will comprise a 500 watt 60 cycle trans- 
(Continued on page 137) 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



131 



Who Gets $200,000,000 

Tire Profits? 

An amazing condition revealed in the tire business. Terrible 
waste shown by methods of selling automobile tires. How one 
tire man plans to cut the cost of tires to the consumer revealed 

Tire Chain Stores Offer Solution of Problem 

By M. E. PHILLIPS, "Staff Correspondent" (Home Magazine) 



NOTE. — The following article, written by our staff representa- 
tive, outlines plans for a giant chain of tire service stations and 
stores which it is predicted will greatly lower automobile upkeep 
costs. A unique co-operative plan which has been tested out 
and found successful. Output of splendid factory already secured, 
more to follow. The success of other chain stores and the tre- 



mendous growth of the automobile industry — consequently of 
the tire business — makes this one of the most attractive and in- 
teresting enterprises. We have made every effort to verify the 
statements made here and to the best of our knowledge the 
statements are accurate and the estimates conservative. — (Pub- 
lisher Home Magazine.) 



Who gets the $200,000,000.00 A YEAR TIRE 
PROFITS? 

Do you know that the cost of producing a tire 
is possibly ONE-THIRD of the price you have 
to pay? That a small tire you pay $15.00 for 
costs about $5.00 to manufacture? That the 
tire costing about $20.00 to build lias to retail 
for about $60.00? 

Do you know that the tire manufacturer is 
satisfied to sell his tires for very little over 
the cost, and at only a fraction of the retail 
price? 

Where does the balance go? 
Who then gets this enormous "cut in" on 
the tires vou buv? 

DO YOU? Of course not. 
Who, then? 

Well, the JOBBER gets a BIG slice. 
The WHOLESALER gets another BIG 
slice 

The RETAILER gets HIS SHARE. 

The rest goes into advertising, dealer's helps, 
adjustments, etc. 

Meanwhile YOU, Mr. Tire Buyer, pay the 
100 per cent price and worry about the high 
price of upkeep of your motor car. 

WILL CUT TIRE COSTS 

A clever tire man, a man with intimate 
knowledge of the tire industry, a man with 
breadth of vision and economic principles, has 
seen this enormous WASTAGE in the tire 
business and has evolved a PLAN that will 
revolutionize the tire selling business. 

He argues that TIRES COST THE CONSUMER TOO MUCH. 

He says there is no reason on earth why the tire buyer should 
have to pay this enormous burden of profits and selling costs. 
If tires can be made for ONE-THIRD of the actual retail prices 
they can be sold FOR LESS than prices now charged for them and 
still pay legitimate profits. LARGE PROFITS, because of the 
volume of business a company offering such savings is bound to 
achieve. 

This far-sighted man is a PRACTICAL TIRE MAN. As a 
manufacturer he has MADE GOOD. He is a PRACTICAL 
BUSINESS MAN, with all a practical man's dislike for waste. 
He has proved his genius for organization and big things. 

This man is Mr. J. G. Feist, President of the National Rubber 
Company of New York. 

PLANS CHAIN OF STORES 

_ Mr. Feist's plan is to establish a chain of tire service and store sta- 
tions from Maine to California, and Canada to the Gulf of Mexico. 

The National Rubber Company of New York has been organized 
with strong men behind it and it has already secured the output 
of one entire factory as the nucleus of this chain store plan. 
More factories will be added as the chain extends and the need 
of more tires becomes evident. The first factory whose product 
has been acquired is the National Rubber Company of Pottstown, 




The Famous Philadelphia Experimental Tire Service Store that Proved to President Feist 
of the National Rubber Company the Practical Possibilities of Tire Chain Stores, Located 
at the Corner of North and Broad Streets. 



Pa., manufacturers of the famous National Speedway Tires and 
National Red Tubes. 

The NATIONAL SPEEDWAY REDWALL TIRES are so 
GOOD that they are sold under the strongest GUARANTEE 
to be had. 

The company agrees to replace FREE any tire that does not 
outlast and outwear any tire of any make or price of the same 
size tested under the same conditions. 

This company now has a production of 1,000 tires and tubes a 
day and is being enlarged to a much greater capacity. When 
the distribution exceeds the capacity of this plant, new plants will 
be started or bought in different sections of the country, or their 
outputs contracted for in order to bring up the production to the 
necessarv number of tires. 

Mr. Feist proposes to sell tires at a MUCH LOWER PRICE 
than is now being charged for good tires elsewhere. 

He plans to give SUPERIOR SERVICE to tire buyers. 

He will give them a BETTER TIRE. He anticipates that in 
doing this his company will prove the greatest profit maker in 
the country. 

EXPERIMENTAL PLANT A SUCCESS 

Mr. Feist is not building his company's future on imagination 
or theory. Before maturing his plans he opened in Philadelphia 



132 



THE ELECTRICAL EXPERIMENTER 



June, 1917 




Boston Service Store of National Rubber Company, Located at 557 
Columbus Avenue. 

a station such as he proposes to establish elsewhere. 

This is what his Philadelphia service station and store does : 

It sells tires below the average price of high-class tires of equal 

size and quality. 
It delivers tires PUT ON YOUR CAR. 

You phone in that you need a 34x4 tire and give your address. 
A mechanic picks up the required tire, puts it in the carrier of a 
motorcycle and speeds off to your address. On arrival he takes 
off your old tire and puts on the new one. No trouble, no mess. 

If you want your old tire repaired he takes it back with him and 
it is delivered as soon as repairs are made. 

You have saved time, labor, worry and money. 

The success of this first service station PROVES what REA- 
SONABLE PRICES, HIGH QUALITY GOODS, EFFICIENT 
SERVICE will accomplish. Profits are large because of volume. 
The Philadelphia service station already has 11,000 CUSTOM- 
ERS. (Not tire sales, but CUSTOMERS.) 

With this established PROOF of the value of this new departure 
service, Mr. Feist has organized a company to establish National 
Rubber Company SERVICE STATIONS and stores all over 
the country. His plan provides for opening 500 stores the first 
year, if possible, and more stores year by year as the company 
grows. / 

OFFERS GREAT OPPORTUNITIES 

The OPPORTUNITIES offered by this chain of tire service 
stores are self-evident. 

CHAIN STORES of all kinds have been enormously success- 
ful. They have built up some of the greatest fortunes in the 
country. They have made original investors enormously rich. 
And this in spite of the fact that most chain stores have dealt 
only in articles selling for a very small sum. HOW MUCH 
GREATER should be the profits of a chain of stores selling a 
product whose every SINGLE SALE equals the sale of HUN- 
DREDS of the articles sold in most chain stores? ■ ■.■ 

The UNITED CIGAR STORES, selling cigars, cigarettes and 
tobacco, average LESS THAN 20 CENTS PER SALE. The 
National Rubber Company averages MORE THAN $20 PER 
SALE, with proportionate profits. 

THE WOOLWORTH STORES sell 5 and 10 cent articles. 
Yet they have made many millions and the highest office' building 
in the world was built out of these nickels and dimes. 

The REGAL SHOE COMPANY with its chain of hundreds of 
shoe stores, has made its owners rich. So have the Walk-Over 
Shoe Stores, the W. L. Douglas Shoe Stores. All chain stores. 

The TRULY WARNER Hat Store chain has accumulated 
wealth for its owners. 

The Great Atlantic and Pacific Tea Stores, the Jewel Tea 
Stores, the Acme Tea Stores, all chain stores, have made millions. 

The several chains of drug stores, of grocery stores, of cheap 
restaurants, have all made fortunes. 

The reasons for this uniform success are numerous. 

In the first place, operating a "chain of stores" of any kind 
reduces the cost operation — what is known as OVERHEAD EX- 
PENSE — to the minimum. 

Secondly, the purchasing power of the buyer who buys for 
hundreds of stores is so enormous that he can pretty nearly make 
his own price. He gets ROCK BOTTOM costs on everything. 
Woolworth can sell for 5 or 10 cents articles that often retail at 
from 25 to 50 cents because he buys outright entire factory pro- 
ductions. The manufacturer who sells his whole output to one 



man for cash, eliminates all selling expense, salesmen, advertising, 
collections, etc., and can sell for a quick turnover, and will yet 
make more profit in the end. That's how the chain store buyer 
can buy at such a low figure that he can sell goods that retail 
generally for 25 cents for 5 and 10 cents. 

Then, the chain store man nearly always buys FOR CASH. 
That means he takes advantage of every cash discount and by 
paying cash he enables his manufacturer to buy for cash and get 
a similar benefit. So it becomes an endless chain of savings which 
benefits the ultimate consumer of the product. 

ECONOMY OF CASH BUYING 

The chain store man uses his cash to buy everything. He buys 
everything the same way. He buys his fixtures, his delivery 
wagons — if he uses them — his every necessity at the lowest bulk 
price, and bulk with the chain store man means tremendous bulk. 

If these chain stores, selling articles that retail for such a small 
price, can earn such fabulous dividends, what will a chain of tire 
service stores earn with the big sales it will make ; sales averaging 
$20 apiece? 

It doesn't take a prophet to look into the future and see the 
magnificent accumulations of dividends that should accrue from 
such an enterprise. 

It isn't hard to foresee what the earnings of such a chain of 
stores can pay in say ten years from today. By that time the 
chain should extend to every city of any importance in the coun- 
try. This may mean thousands of such stores, because there are 
in the United States 1,442 towns of 5,000 or more inhabitants 
and over 100 cities having a population of 55,000 or over. The 
small towns, say the towns under 10,000, would require only 
one such service station, while the larger towns would require 
a number of them. 

THOUSANDS OF CHAIN STORES 

To give you an idea of how many stores some of the big chains 
have, it is enough to mention the Great Atlantic and Pacific Tea 
Company, with over 1,500 retail stores ; the United Cigar Stores, 
with over 1,000 retail stores ; the, Woolworth Company, with over 
1,000 stores, etc. 

The tremendous growth of the automobile industry — a growth 
that is gathering size and importance every day — makes this pro- 
jected chain of tire service stores all the more important. 

At the beginning of 1917 there were approximately THREE 
MILLION autos in use in the United States. According to last 
United States census, there were in 1910 (date of last census) 
91,972,266 inhabitants in the U. S. It is calculated that there are 
now at least 120,000,000 people in the U. S. At this rate, there 
is one auto, in the U. S. for every 40 people. In many of the 
states, the ratio is higher than one for every 16 people. This 
means that THERE IS A TREMENDOUS POSSIBILITY FOR 
MORE MACHINES. 

According to the best informed automobile authorities, it is 
calculated that there will be added at least 1,000,000 auto users 
during the year 1917, bringing up the total close on to FOUR 
MILLION AUTOS in actual use in the U. S. With such an 
enormous distribution of cars, and all the automobile factories 
of any account way behind in deliveries, an enormous supply 
of tires will be required to keep these autos running. 

24,000,000 TIRES NEEDED 

Very moderate estimates place the number of tires required 
on each car at EIGHT PER YEAR. Each auto MUST HAVE 
FIVE TIRES, four on the wheels and one spare tire. It is an 
ultra conservative estimate, therefore, that places the required 
number of tires to meet the needs of 1917 at SIX PER CAR. 
At this rate 4,000,000 automobiles will require 24,000,000 tires. 
This is truly AN AMAZING FIGURE for an industry that is 
only a little over a dozen years old. 

The distribution of these cars is centered at present in certain 
sections. When the other sections have awakened to the advan- 
tages and uses of the automobile and its economj- for travel and 
commercial purposes, it is more than likely that the distribution 
will be much more even. 

It has been estimated by statisticians that there are OVER 
TEN MILLION men in the U. S. who should be, and probably 




Chicago Store of National Rubber Company, the Third in the Chain. 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



133 



soon will be, auto owners. These are men who, because of their 
business, their financial condition and their position, should be- 
come automobile owners. 

There are upwards of seven million farmers in the U. S., and 
of these a large percentage will probably become owners of auto- 
mobiles. Just now only about 7 per cent of the prosperous farmers 
own automobiles. The farmer is today the RICH MAN of the 
U. S. He has been getting the biggest prices ever paid for crops, 
he has by scientific farming increased the yield of his acres, 
and he has been fortunate in getting big crops when the price 
was highest. 

For these reasons, THE FARMER IS USUALLY PROS- 
PEROUS and lie is putting some of his riches into the comforts 
and conveniences of an automobile. 

With such prospects, with such a tremendous field to concpier, 
with the SUCCESS that has attended the FIRST UNIT of the 
National Rubber Company chain of service stores, it is not hard 
to visualize the ENORMOUS POSSIBLE PROFITS from this 
enterprise. 




Officers and Officials of the National Rubber Company of New York. These Men 
Have Made the Making and Selling of Tires Their Life Work, Both as Manufacturers 
and Branch Managers. They are Pioneers in the Tire Business; They Have Watched 
the Tire Business Grow from the Experimental Stage. Today They are Large Fac- 
tors in the Manufacturing of the Best Tire that Money Can Make. Mr. Walsh, Who 
Is Superintendent of the Plant, Has Been for 23 Years in Active Charge of the 
Making of the Best Known Tire in America. Mr. Sperry Was With the Deere Plow 
Co. as Agency Organizer. Mr. Dougherty Has Been a Tire Representative for Years, 
Formerly With the Lee Tire Co. H. A. Lamoree Has Also Been a Branch Tire Store 
Manager and General Tire Salesman With Several of the Big Companies. 

HOW PROFITS PILE UP 

Even a casual consideration of the subject makes the figures 
run into such amazing columns of profits that the very thought 
is staggering. 

The great earnings of chain , stores of all kinds has been in 
the aggregate. 

When you take 1,000 stores and pile their profits in one great 
heap, you have a formidable aggregate — an aggregate which 
doesn't have to be very large in the individual case to make up 
this magnificent total. 

Let us take into consideration one unit and then see how it 
works out. 

Firstly, we must remember that these service stores are oper- 
ated at a minimum of expense. Being administered from the 
central office, whose costs of operation are spread over the whole 
chain, the local stores require only inexpensive help. The man 
who operates a store of his own expects to make A GOOD 
LIVING out of it for himself AND A GOOD PROFIT besides; 
he has to pay for everything on the high price of individual 
He has to have efficient help, has to advertise and, 
he has fixed charges for rent, light, taxes, insur- 



purchases. 
of course, 
ance, etc. 



CHAIN STORE SAVINGS 

The chain store hires only the necessary help, it eliminates 
the owner's living and profits. It buys in enormous quantities 



at prices that make the prices the individual store owner pays 
seem preposterous ; it pays the minimum for taxes, for insur- 
ance and the advertising expense of operating is carried in bulk 
by the parent company, and this is divided pro rata so that each 
individual store pays only a small sum as its share of the adver- 
tising expense. 

Tires are bought at actual contract price from the manufacturer 
and so charged agains the store, much cheaper than the average 
tire store man can buy them. 

We then have EXPENSES PARED DOWN TO THE BONE, 
probably HALF WHAT THEY WOULD BE UNDER ORDI- 
NARY CONDITIONS. And we have the most attractive kind 
of a proposition to offer to the tire buvej — THE BEST TIRE 
ON THE MARKET AT MUCH LESS than he would have to 
pay elsewhere; A SERVICE NO OTHER TIRE CONCERN 
GIVES or can give, GUARANTEED SATISFACTION backed 
up by a company operating a nation-wide chain of stores. 

With so much to offer and with such splendid profit-making 
advantages it is not hard to look into the future and see every 
store paying a big profit and the company earn- 
ing dazzling dividends. 

What may one store earn, you may ask? 
Let us do a little figuring : 

Firstly, the ENTIRE FACTORY SELLING 
EXPENSE IS ELIMINATED— the entire output 
of the factory being sold to one customer — the 
chain store. 

The saving of the traveling expense and sales- 
man's salaries and commissions. The saving of 
advertising and promotion expense. The added 
office accounting and credit expense. All these 
are SAVED by the chain stores. In these items 
alone is found a selling cost of at least 20 per cent. 

On top of that the JOBBERS' DISCOUNT OF 
40 PER CENT IS WIPED OUT. 

No thinking man or woman has to be told that 
the NET SUM the manufacturer receives ALONE 
CONTROLS THE QUALITY AND QUAN- 
TITY of materials used in making tires, because 
ONLY AND SOLELY from this NET SUM is 
the PROFIT derived. 

Because of the TREMENDOUS OVERHEAD 
selling and distributing expense, the enormous dis- 
counts demanded by the jobber, the wholesaler and 
the retailer, if the manufacturing cost were TOO 
HIGH or even over his competitors, then added 
charges, as described here, increase out of propor- 
tion and the consumers' prices would be prohibitive. 

Hence, in National Speedway Tires most of the 
factory selling cost is put in the tire in ADDED 
QUALITY AND QUANTITY, and the usual 
trade discounts are divided with the consumer. 

PROFITS OF CHAIN STORES 

We now come to the question of the profits of the 
chain stores of each unit and of the chain in the 
aggregate. 

After a careful scrutiny of costs of manufac- 
turing, of operating the chain store — each unit — 
and figuring a retail price on the tires at a sensible 
reduction over average price of tires of equal size 
and quality we find that there is still possible an 
average margin of $5 per tire. This is "AVER- 
AGED" because some of the tires will pay more 
profit while some will pay less, but the average has been shown to 
be about $5 per tire sold. 

This is evidently a CONSERVATIVE ESTIMATE. 
If each chain store sells ONLY 10 TIRES PER DAY, we 
have each store earning a profit of $50 a day or $50,000 a day 
profit for 1,000 stores. 

$50,000 profit per day for 365 days in the year — tire service 
stations are busier Sundays and holidavs than other davs — FIG- 
URES OUT THE ENORMOUS TOTAL OF $18,250,000 A 
YEAR PROFITS. 

You will realize that an estimate of only ten tires per day 
is very small. When you consider the tremendous advantages 
of dealing with the National Rubber Company service stores, 
the high class product, the low price, the good service given in 
the way of instant special deliveries, placing the tire on the car 
and taking away the injured tire for repairs, it is not hard to 
understand why these stores should do an enormous business. 

Ten tires per day is a very low estimate of the possibilities, 
but to be even more conservative, let us cut down this estimate 
by half. Let us suppose that the stores onlv AVERAGE FIVE 
SALES PER DAY. Let us see how this figures out. 

FIVE TIRES A DAY, showing an average profit of $25 per 
day per store, one thousand stores will, therefore, pay an esti- 
mated daily profit of $25,000. For 365 davs in the year, THE 
ENORMOUS TOTAL WOULD ■ BE $9,126,000, and it would 
be a mighty small store that couldn't sell five tires per day. 



134 



THE ELECTRICAL EXPERIMENTER 



June, 1917 



These figures are staggering when you analyze the accumu- 
lated profits of hundreds of stores all over the country, each 
contributing its quota of profits from many sources. 

A GOLD MINE OF PROFITS 
You will note that no estimate has been made of profits from 
sale of tubes and from the repair department, which should also 
be profitable. 

It will, of course, take time to build up such a large chain 
of service stations, but in a few years, with the growth of the 
chain and the enormous increase in the automobile industry 
and number of cars in use, THIS CHAIN OF TIRE SERVICE 
STATIONS SHOULD BECOME A VERITABLE GOLD 
MINE OF PROFITS FOR EVERY STOCKHOLDER WHO 
BECOMES INTERESTED IN THIS COMPANY NOW, when 
its shares can be acquired at a low initial price. 

The National Rubber Company, of New York, is incorporated 



WHAT THIS MEANS TO AUTOISTS 

Let us study it over. $50 invested in ten shares of this under- 
writing stock will save the automobile owner 25 per cent on 
his tires. If his bill for tires runs to $200 a year, he will be 
saved, therefore, $50. That means that the stock will have paid 
him 100 per cent on his investment or 50 per cent on the par 
value of the stock, which, computed on a stock's ability to earn 
5 per cent, will make his TEN SHARES REPRESENT AN 
INVESTMENT OF $1,000 FROM AN ORIGINAL INVEST- 
MENT OF $50. Then if the company begins paying dividends, 
the stock should go to par and over if the dividends amount 
to more than 5 per cent. 

When the company gets on a 10 per cent dividend basis, the 
stock he bought for $50 should represent an investment of $200. 
When it pays 50 per cent, it should have an INVESTMENT 
VALUE OF $1,000, 




Section of Tire-making Department. Here a Small Army of Workmen Are Constantly Employed Putting 
the Finishing Touches to National Redwall Speedway Tires. These Workmen Are the High-skilled 
Labor and Their Rapidity and Efficiency Are Wonderful. 



under the laws of the State of Delaware, with a capitalization 
of 500,000 shares of the par value of $10 PER SHARE, ALL 
COMMON STOCK, SHARING EQUALLY IN PROFITS 
AND CARRYING FULL VOTING POWER. 

THE STOCK IS FULL PAID AND NON-ASSESSABLE. 

For the purpose of establishing the business on a right basis, 
the directors have set aside 100,000 SHARES OF THIS STOCK 
TO BE SOLD TO THE PUBLIC. 

Their idea is that by obtaining a wide distribution for this 
stock, they will enlist local interest in the local distributing and 
service stations of the National Rubber Company. 

UNDERWRITING STOCK OFFER 
This UNDERWRITING SYNDICATE STOCK is offered in 
five different allotments. 

The first allotment will be sold in lots of not less than TEN 
SHARES and not more than 100 shares at $5 per share, or 
half the par value 6f the stock. 

This first allotment of 20,000 shares is the only stock of the 
UNDERWRITING allotment that will be sold at this low price. 
The next allotment will probably be sold at from 40 to 50 per cent 
advance in price as soon as the first allotment of 20,000 shares 
is disposed of. Further allotments at further increases as war- 
ranted. 

It is desired — as nearly as possible — to place every share of 



So when the company is in a position to pay 50 per cent 
dividends, this stock should represent an investment to the auto- 
mobile owner of $2,000, figured on the basis of the dividends and 
savings it will give him on his tire purchases. And all from 
an original investment of $50. 

When the company reaches its full development and its 1,000 
or more stores begin piling up big profits, such as we have already 
ficured on, profits that mean exceptional dividends, THIS ORIG- 
INAL INVESTMENT WILL HAVE ACCUMULATED A 
PHENOMENAL VALUE. 

NO AUTOMOBILE OWNER CAN AFFORD TO OVER- 
LOOK SUCH AN OPPORTUNITY. 

A blind man could see the possibilities presented in this under- 
writing offer, an offer so liberal that the directors had to confine it 
to a small amount of stock. 

AN EXCEPTIONAL OFFER 

The offer of the stock at $5 per share (par $10) is in itself 
a tremendous inducement, but when it is coupled with the offer 
of the company to extend a discount of 25 per cent on all tire 
and tube purchases made through the company, it becomes so 
extremely attractive a proposition that NONE CAN AFFORD 
TO IGNORE IT. 

The savings in tire costs alone should pay for the stock of 
those who accept this offer. 




The Splendid Modern Character of This Ideal Plant Is Shown Clearly in These Pictures, With Its Strong, 
Clear Light, Fine Equipment and Good Flooring. Ideal Conditions for Turning Out High-class Work. 



this UNDERWRITING stock in the hands of owners, or pros- 
pective owners, of automobiles, who will become immediate pa- 
trons of the chain stores and who ARE ALSO OFFERED AN 
INDUCEMENT TO BECOME BOOSTERS FOR THE TIRE 
SERVICE STATIONS. THIS INDUCEMENT CONSISTS 
OF A CASH DISCOUNT OF 25 PER CENT UNDER THE 
STANDARD LIST PRICES FOR ALL TIRES SOLD BY 
THE NATIONAL RUBBER COMPANY TO ITS SHARE- 
HOLDERS. 

An automobile owner, therefore, has a double interest in buy- 
ing this stock. 

The saving alone in tire bills for a year should pay for this 
ten shares if he buys at this price and he will have, besides 
the savings in tire costs, and dividends which the company de- 
clsrcs 

IS THIS INVESTMENT WORTH WHILE, you may ask? 



This, in itself, makes the proposition attractive. But when the 
future of this company is analyzed and the possibilities it offers 
are considered, the offer becomes immensely more attractive. 

YOU NEED NOT NECESSARILY BE AN AUTOMOBILE 
OWNER today to accept this offer. Your stock in the National 
Rubber Company will entitle vou to this 25 per cent discount 
on tires and tubes JUST AS LONG AS YOU REMAN A 
STOCKHOLDER. Later, when you buy an auto, you'll be able 
to buy tires at this great saving. 

You often hear it said that if you had a chance to invest 
with Ford, or Willys, of Overland fame, with Goodrich or Fisk 
or Firestone ; with Westinghouse or Bell, or some of the others, 
whose companies have earned fabulous dividends, and made 
stockholders rich, you would today be ON EASY STREET. 

This is verv true but the pitiful truth is YOU DID NOT HAVE 
THIS CHANCE. VERY FEW PEOPLE DID. These com- 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



135 



panies were all close corporations with the stock held in the 
hands of a small group of men. These stocks were not offered 
to the puljlic. 




Tire Fabric Cutting Machine. This Machine Can Cut the Fabric for 
1,000 Tires a Day, Doing the Work of 10 Men. 

A CHANCE IN A MILLION 

BUT HERE IS A CHANCE. Here is a company offering 
UNDERWRITING STOCK, stock that can now be bought at 
the ROCK BOTTOM PRICE, that should in time become 
enormously remunerative. Stock in a company that promises 
to have tremendous growth. 

Woolworth and Whalen and the others, who have made tens 
of millions out of chain stores, never gave the public a chance 
to come in on the organization. They have sold stock since, 
lots of it to the general public, but it has been stock in the 
developed proposition, stock that has been sold on the market AT 
THE VALUE IT PRESENTS NOW, a value figured on the 
company's earning power. 

LATER YOU MAY GET A CHANCE on the National Rub- 
ber Company stock on the open market but YOU'LL PAY THE 
PRICE OF DEVELOPED STOCK. If the company is earn- 




Tire-Making Machines. A Busy Corner in This Department. These 
Four Machines Shown in the Picture Do the Work of 40 Men. This 
is the Most Modern Tire-making Machine Built. 

ing 100 per cent on its capitalization, you'll pay for it at that 
rate, which, in that case, would be $2,000 for every $100 par 
value, or $200 a share for $10 shares. 

THIS IS THE PENALTY THAT SHORT-SIGHTED 
PEOPLE PAY for not accepting opportunities that are offered 
them. 

The poorhouse is FULL OF SUCH PEOPLE, "THE MIGHT- 
HAVE-BEENS." 

They lacked the initiative and courage to back their belief 
with their money. 

THOSE WHO HAD COURAGE 
The others, those who are without fear, those who have the 
courage to back their judgment with their money, they are those 
you watch spinning past you on the boulevard in luxurious 
limousines, whose homes line the fashionable streets. 

MONEY MAKES MONEY, but it takes an exceptional op- 
portunity to bring you big returns from small investments. You 
read, for instance, that $500 invested in such-and-such stock 
has earned $250,000 ; that $500 invested in such other stock has 
paid $200,000; that $1,000 in Ford stock of the original com- 
pany is now worth millions. THAT IS ALL TRUE, gospel 
truth, BUT did YOU ever get a chance to invest in the orig- 
inal $28,000 that started Ford on the highroad to his present 
millions? Did you get a chance to invest in the $33,000 that 
John N. Willys has built up into the tens of millions of the 
Overland Company? Did YOU get a chance to get in on West- 
inghouse, or Bell Telephone, or Western Union, or Welsbach 
Mantles stock? Of course not. And very few people did BE- 
CAUSE THESE STOCKS WERE NOT OFFERED TO THE 
PUBLIC when they were at a low price. 

THERE'S A REASON 
This stock is offered for a reason. 

It is offered to the UNDERWRITERS of this company to 
start it with a nucleus of interested tire buyers and boosters in 
every locality. 

The directors set A MINIMUM OF TEN SHARES AND 
A MAXIMUM OF 100 SHARES on this offer. It would doubt- 
less be more profitable to the company if every subscription for 
this stock was for $50 (10 shares), par value $100, because 
that would mean that the greatest number of people possible 




Vulcanizing Department of the Pottstown Plant. Here the National 
Speedway Tires Are Hardened to Stand Wear and Tear. This De- 
partment is Now Vulcanizing 1,000 Tires a Day. 

would be holding the stock and boosting for the company. 

Ten thousand holders of stock scattered throughout the coun- 
try would mean a veritable army of boosters, helping build up 
the business IN WHICH EACH ONE HAS A SOLID, SUB- 
STANTIAL INTEREST. 

Ten thousand boosters, working to popularize and make known 
the high quality of National SPEEDWAY RED-WALL TIRES 
and National Red Tubes — boosting this way because it is TO 
THEIR INTEREST to boost this way— would save the com- 
pany tens of thousands of dollars per annum in advertising ex- 
pense. 

That's the principal REASON WHY THIS STOCK IS OF- 
FERED TO YOU AND TO EVERYONE WHO BUYS TIRES 
OR EXPECTS TO BUY TIRES. 

It is WORTH IT to the company to make you EVERY IN- 
DUCEMENT to buy this stock. AND IT IS CERTAINLY 
WORTH WHILE TO YOU TO BUY IT. Remember you 




Rubber Vault. In This Vault Are Stored Thousands and Thousands 
of Pounds of Uncured Rubber for Tire and Tube Making. It is Stored 
Here Just as It Comes from the Ships. 

profit immediately because as soon as you are a stockholder 
you can save 25 per cent on all the tires you buy. 

WAITING FOR A MIRACLE 

Every man hopes, some day, that by some wonderful miracle 
he will be lifted out of the life of drudging toil he leads into 
one of affluence, comfort and independence. It is our nature 
to live in this HOPE. But the day of miracles is past. Good 
fairies do not run around with bags of gold and drop them into 
the laps of the worthy. 

YOU'VE GOT TO HELP YOURSELF TO FORTUNE. 
You've got to save to get a nucleus of money to invest where 



136 



THE ELECTRICAL EXPERIMENTER 



June, 1917 




Tube-making Department. Here Are Made the Famous National Red 
Tubes. The Factory is Producing 1,000 Tires a Day. 

the opportunities for profit are large. BUT YOU'VE GOT TO 
INVEST YOUR SAVINGS, if you want them to pay big re- 
turns. 

One of the world's greatest bankers has said that NO MAN 
WILL EVER GET RICH FROM THE SAVINGS OUT OF 
A SALARY OR WAGES. He must accumulate wealth by 
PUTTING THESE SAVINGS TO WORK, INVESTING 
THEM TO ADVANTAGE. 

Of course, it takes COURAGE to invest money that you 
have worked hard for, that has been slowly and laboriously 
accumulated by privations and sacrifices. But IT IS THE 
COURAGEOUS WHO WIN THE EARTH. 

DON'T INVEST ALL YOUR SAVINGS. That wouldn't be 
the wise course. Keep a reserve of your savings for eventualities, 
for sickness or loss of position or unexpected calls, BUT IN- 



first allotment of 20,000 shares at $5 a share (par value $10 a 
share) will be snapped up so quickly that WE CONFIDENTLY 
EXPECT EVERY SHARE TO BE TAKEN UP WITHIN 
TEN DAYS from the publication of this announcement. After 
that, there will be no more $5 shares. The price will jump per- 
haps 40 or 50 per cent. SO ACT NOW. 

Fill out the convenient coupon attached. Mail it with your 
first payment, which will RESERVE the stock you want at this 
LOW PRICE. Then you can take fifteen days to investigate, 
to make sure that all the facts are just exactly as represented to 
you. If you, for any reason whatever, are not satisfied, you can 
release your reservation and your money will be returned to you, 
but if you find out that you have invested wisely — as we are confi- 
dent you will find out — then you can either pay the balance in full 
or you can take advantage of the easy method of paying for it, a 
little each month. Either plan is equally satisfactory to the 
directors of the National Rubber Company of New York. 

IF YOU WANT ANY OF THIS UNDERWRITERS' 
STOCK, YOU'VE GOT TO WRITE NOW, at once, OR YOU 
WILL LOSE YOUR CHANCE. 




The Magnificent Pottstown, Pa., Plant of the National Rubber Company, Where National Speedway Redwall Tires and National Red Tubes 
Are Made. Two Floors of This Big Building Are Completed and Occupied. This Is a Strictly Modern Steel, Concrete and Glass Construc- 
tion Factory Building of the Highest Type. The Big Tire Coming Out of the Building is the National Speedway Redwall Tire, Best on the 

Market. 

VEST PART OF YOUR SAVINGS WHERE THEY CAN 
EARN YOU SOMETHING WORTH WHILE. 

INVEST FUTURE SAVINGS 
Or better still, HERE IS A PLAN BY WHICH YOU CAN 
ACQUIRE THIS STOCK WITHOUT TOUCHING YOUR 
SAVINGS. 

BUY WHAT YOU CAN AFFORD TO PAY FOR OUT OF 
YOUR NEXT SAVINGS 
The directors have made it EASY FOR YOU TO GET THIS 
STOCK AND PAY FOR IT OUT OF YOUR FUTURE SAV- 
INGS. 

You can pav down $10 ON EVERY TEN SHARES OF 
STOCK YOU WANT AND PAY THE BALANCE IN FOUR 
EQUAL PAYMENTS OF $10 A MONTH for each 10 shares, 
making the total of $50 for the ten shares, par value $100. 

This liberal plan makes it possible for you to buy this stock 
and pay for it WITHOUT TOUCHING THAT PRECIOUS 
CASH RESERVE you have been accumulating in the bank so 
carefullv. 

BUT' WHATEVER YOU DO, DON'T OVERLOOK THIS 
OPPORTUNITY. You'll never get another such chance. This 





How You Can Buy This Stock 






10 shares (par value $100) 




$10 


down, $10 a month for 4 months 


$50 


15 shares (par value $150) 


$15 




$75 


20 shares (par value $200) 




$20 


down, $20 a month for 4 months 


$100 


30 shares (par value $300) 




$30 


down, $30 a month for 4 months 


$150 


40 shares (par value $400) 




$40 


down, $40 a month for 4 months 


$200 


50 shares (par value $500) 




$50 




$250 


$100 shares (par value $1,000) 




$100 down, $100 a month for 4 months 


$500 



APPLICATION FOR UNDERWRITERS' SHARES 

E. E. 

NATIONAL RUBBER COMPANY OF N. Y., Pottstown, Pa. 

Main Office: National Rubber Bldg., Broad and North Sts. „ , 

PHILADELPHIA, PENNA. Date 191.... 

The undersigned hereby subscribes for. shares of the Common Stock of the 

National Rubber Company of New York, full paid and non-assessable, and tenders herewith v- - : 

(Bank Check or Money Order) 

to the order of National Rubber Company of New York for $ ■ at the rate of $5.00 

per share J full } payment, 
j part \ 

STOCKHOLDER'S DISCOUNT — It is understood that in consideration of this subscription as long as I remain 
a shareholder of record on the books of the Company, I am to receive a Net Cash Discount of not less than twenty- 
five Per Cent (25 per cent) from the Company's regular Printed Price List, on -any goods listed therein which 
I may buy for my own use. I am to have 15 days from date in which to investigate all statements made by 
the Company. 

Issue shares in the name of and forward to addres below: 

(Print Name Plainly) 

(Subscriber's Signature) 



(Street Address) 



(Town and State) 



Mr. Edison's y »v.;;. r .';i 

— . . ' ...j- -^ — 



June, 1917 



THE ELECTRICAL EXPERIMENTER 



QUESTION BOX. 

(Continued from page 130) 
former, having a secondary potential of 
10,000 volts. This to charge a group of 
four Murdock block condensers that will 
be connected in parallel. The discharge to 
take place in a quenched spark gap linked 
to a primary of an inductive oscillation 
transformer. The secondary to be connect- 
ed in the usual way to the antenna and 
ground terminals. What I desire to know 
is what size of capacity of condenser is 
required to reduce the wave length of my 
oscillating system so as to conform to the 
Government's 200 meter wave length regu- 
lation? What formula do you employ in 
determining this capacity? 

A. 2. The required formula is : 
X 2 C 

Ci = ; 

3552 L C — \ 

Where 

Ci is the capacity of the series ground 
condenser for reducing the wave 
length 

Xi=wave length desired (here it is 200 

meters) 
C = Capacity of the antenna 
L = Inductance of antenna 
Having calculated the values of the capa- 
city of the antenna .0004 mfd. ; inductance 
62,090 cm., we then determine the desired 
capacity by substituting in the above for- 
mula and we get : 

(200)= X .0004 

Ci = - — — ; 

3552 X 62090 X .0004— (200) 2 
Solving, we get .003 micro-farad, the 
capacity of the condenser necessary to re- 
duce the wave length of the antenna to 200 
meters. 

ELECTRON DISCHARGE. 

(790.) Louis Bradenburg, Little Rock, 
Ark., wants to know : 

Q. 1. Does the effect of light upon 
selenium crystal produce a purely electronic 
discharge? 

A. 1. This question is still in the hands 
of some prominent physicists, and they have 
not come to any conclusions on this mys- 
terious problem, and for this reason we are 
unable to give you an exact answer. We 
should recommend, however, that you read 
an article on selenium in this issue, written 
by two of the most prominent and able 
scientists on this subject. 

Q. 2. I have had an idea for a number 
of years to make an electronic detector for 
converting high frequency currents to 
direct or pulsating currents, or in other 
words an instrument similar to the Fleming 
Valve and de Forest Audion. Now what 
I desire to know is, what chemical will pro- 
duce an electronic field sufficiently strong 
for producing the same effect as that of the 
lighted filament? Also, was there any such 
device ever made? 

A. 2. Dr. J. A. Fleming, the inventor of 
the Fleming Valve, has built electronic 
tubes employing an exhausted vessel in 
which an amalgam of Sodium and Potas- 
sium was placed in such a manner that it 
produced an electronic field when a beam 
of light was focussed upon its surface and 
in addition a secondary plate was placed 
within the focus of the electronic stream. 
The secondary and sodium-potassium plates 
were used for the rectifier circuit of the 
electronic tube. 

The two most generally used of all the 
metals and alloys for the production of an 
electronic field are chemically pure and 
highly polished rubidium metal and an alloy 
composed equally of sodium and potassium 
metals. 

TONE CIRCUIT. 

(791.) Roy Jansen, Houston, Tex., 
asks : 



MEDICINE HAILS ELECTRICITY. 

"The day of the howling dervish in elec- 
tro-therapeutics is past," declared Dr. S. 
Solis Cohen in the meeting recently of the 
Philadelphia County Medical Society, "and 
the science now has a definite, dignified 
place in the estimation of the medical pro- 
fession and of the public." 

"We must confess with shame," said Dr. 
S. Lewis Ziegler, "that the greatest ad- 
vances in the application of electricity to 
medicine have come thru laymen and not 
doctors." 

Dr. A. B. Hirsh traced the history of 
electro-therapeutics, and declared that an 
astonishingly large number of diseases re- 
sponded to electric treatment. 

Q. 1. What does a "tone" circuit con- 
sist of and how is it connected to a radio 
transmitter ? 

A. 1. A tone circuit consists of nothing 
more than an oscillatory circuit shunted 
across the gap. This circuit is shown here 
and it is only used in an impulse exciting 
transmitter usually. The tone circuit is 
represented by the oscillatory circuit L Ci. 
A large capacity and a small inductance is 
used. 

Q. 2. Is this circuit tunable? If so, 
how? 

A. 2. The tone circuit is tuned to some 
multiple or sub-multiple of the impulse 
frequency. This is usually accomplished 
by varying the tone circuit condenser capa- 
city. It should be kept in mind, that a 
tone circuit does not improve the tone 
emitted by the transmitter in every type 
of gap, as it was found by actual experi- 
ment that at times it is even detrimental 
to the tone. They are usually employed 
on low tension arc or spark transmitters 
such as the Von Lepel or Chaffee Arc. 




Arrangement of Tone Circuit in the Von 
Lepel and Chaffee Arc Radio Transmitter. 



MAGNETIC TELEPHONE. 

(792.) William Olsen, Jamaica, L. I., 
desires to know : 

Q. 1. What is the principle upon which 
two ordinary telephone receivers when 
connected together can transmit the human 
voice from one place to another by talk- 
ing to the diafram of either of the two 
receivers ? 

A. 1. The principle of operation of 
such a telephone is identical to the pro- 
duction of electric current by a dynamo- 
electric machine, in that when a magnetic 
field is permitted to be interrupted by a 
wire near its field, a current of electricity 
is produced in that wire and the intensity 
of the generated current is dependent upon 
the rapidity with which the magnetic field 
is interrupted and the intensity of the field. 
It is identical with the magnetic telephone 
where the permanent magnet of the re- 
ceiver furnishes the magnetic field, the coil 
of wire or electro-magnet represents the 
wire, while the interruption of the mag- 
netic field is obtained in this case by the 
vibration of the magnetic diafram. When 
the diafram of the receiver is caused to 
vibrate by "talking," the magnetic flux is 
varied ; generating a current in the coil 
which operated the distant receiver. 




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138 



THE ELECTRICAL EXPERIMENTER 



June, 1917 




Save Dictating Time 

USE THE DICTAFORM 

If you are at present keeping one or more stenog- 
raphers busy — you need the Dictaform. It will 
mean the saving of valuable time in the handling 
of your correspondence. Surprisingly few letters 
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Banish Dictating Bother 

The Dictaform places at instant reference paragraphs, phrases and arguments sparkling with 
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A GENUINE "RED DEVIL" GLASS CUTTER FOR 10c 

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HIGH FREQUENCY PHENOMENA. 

(793.) S. Kohn, Brooklyn, N. Y., asks: 

Q. 1. Can you explain the following 
phenomena which I recently observed dur- 
ing certain experiments which I have car- 
ried on with a Tesla high frequency coil? 

A large primary of a loose coupler was 
located near the Tesla coil ; this was about 
3 feet away from the same, and it was 
not connected to anything. As the Tesla 
transformer was set in operation, I have 
noticed streaks of sparks escaping the 
winding of the isolated coil. If it is pos- 
sible, I should like you to enlighten me 
on this phenomena. 

A. 1. The phenomena which you have 
observed is due to the striking resonance 
effect existing between the Tesla coil and 
the primary coil ; since the resonance was 
pronounced, due to the effect noticed, the 
electrical energy transformation between 
the produced oscillations of the high fre- 
quency coil and that of the isolated coil is 
at maximum ; consequently, the discharge 
of sparks from the coil was produced. 
These resonance high tension and fre- 
quency experiments were carried out first 
by Nikola Tesla, and he was able to ob- 
tain sparks which reached in magnitude 
from five to six feet in length. 



TRANSFORMER FORMULA. 

(•794.) L. Kennedy, Los Angeles, Cal., 
wants to know : 

Q. 1. In the design of a radio trans- 
former, what are the most important pre- 
cautions that must be taken in order to 
build an efficient transformer? 

A. 1. There are a few important steps 
that the designer must observe when de- 
signing a transformer, namely : the voltage 
transformation between the primary and 
secondary, the latter should be made to 
correspond with the proper sending con- 
denser capacity, and this must be obtained 
beforehand ; the proper arrangement of 
secondary pies, separated with proper in- 
sulation, and finally, the magnetic circuit 
in which great care must be exercised in 
designing the same, as 75 per cent of the 
eiheiency will be in this magnetic circuit. 
The proper number of cubic inches of core 
is at first found; this is then split up into 
suitable form, the legs of which should 
correspond to the primary and of the sec- 
ondary windings. 

Q. 2. What is the relation existing 
between the primary winding and voltage 
of a transformer? 

A. 2. The relation of the two factors is 
exprest by the following formula : 

10 s X £ P 

Nv = — — 

V2t fBAc 

Where 

Nv = Number of turns on primary wind- 
ing 

Ev = Voltage across primary 
f — Frequency. 

B = Magnetic flux of core (per sq. cm. 

of cross-section of the iron core) 
A<- = Area (express in square centime- 
ters of the cross-section of the 
iron core) 

Q. 3. What do you consider the best 
insulation material for covering the core 
when the winding is to be made? 

A. 3. Empire cloth is very excellent for 
this work and it is universally employed 
for this purpose. 



THE "BROWN" TELEPHONE 
RELAY. 

(795.) Frank Vontair, Philadelphia, 
Pa., desires to know: 

Q. 1. Is the "Brown" relay, which is 
used in England, a microphone device? 

A. 1. This type of instrument is a 



You benefit by mentioning "The Electrical Experimenter" when writing to advertisers. 



June, 1917 THE ELECTRICAL EXPERIMENTER 139 



purely microphonic device and the micro- 
phone is controlled by a super-sensitive 
telephone relay. A more complete detail 
of this device was published in the Au- 
gust, 1915, issue of